FRÆÐIGREINAR

Hér eru fræðigreinar Rannsókna og greiningar birtar, flokkaðar eftir útgáfuári.


T.I. Halldorsson, A.L. Kristjansson, I. Thorisdottir, C. Oddsdóttir, J. Sveinbjörnsson, R. Benediktsson, I.D. Sigfusdottir, H. Jörundsdóttir, Gunnlaugsdóttir H. Caffeine exposure from beverages and its association with self-reported sleep duration and quality in a large sample of Icelandic adolescents. Food and Chemical Toxiology 157 (2021) 112549.

Previous risk assessments have concluded that adolescent’s caffeine exposure from energy drinks (ED) are of limited concern. Recent surveys have, however, shown substantial increase in consumption. This cross-sectional survey conducted in 2020 estimated caffeine exposure from beverages among ~80% of all 13-15-year-old adolescents (n = 10358) relative to the European Food Safety Authority’s level of no safety concern of (3.0 mg/kg bw) and level for effects on sleep (1.4 mg/kg bw). Associations with self-reported sleep duration and quality were also explored. ED consumers were more likely to exceed the limit of no safety concern (prevelance: 12–14%) compared to non-ED-consumers (1–2%). Exceeding the limit for effects on sleep was also higher among ED consumers (31–38%) than non-ED-consumers (5–8%). Across categories of low (<0.5 mg/kg bw) to high (>3.0 mg/kg bw) caffeine intake, the prevalence of participants sleeping <6 h increased from 3% to 24%, respectively. The corresponding adjusted Prevalence Ratio was 4.5 (95% CI: 3.6, 5.7) and mean decrease in duration of sleep was 0.74 h (95% CI: 0.65, 0.84). In conclusion, caffeine intake from beverages above the limit of no safety concern was largely confined to ED consumers. Consistent with effects from intervention studies in adults, caffeine intake was strongly associated with self-reported sleep duration in this representative population.

Alfgeir L. Kristjansson, Christa L. Lilly, Ingibjorg E. Thorisdottir, John P. Allegrante, Michael J. Mann, Jon Sigfusson, Humberto E. Soriano and Inga Dora Sigfusdottir. Testing risk and protective factor assumptions in the Icelandic model of adolescent substance use prevention. Health Education Research 2020, December:1-10.

Iceland has witnessed a dramatic decline in adolescent substance use that may be partly the result of efforts related to the Icelandic prevention model (IPM). We sought to test risk and protective factor assumptions of the IPM using a prospective cohort study with 12 months separating baseline from follow-up. Participants were students in grades 8 and 9 in the national Icelandic school system enrolled in the spring of 2018 and 2019 (N=2165).

Sigfusdottir ID, Soriano HE, Mann MJ, Kristjansson AL. (2020). Prevention Is Possible: A Brief History of the Origin and Dissemination of the Icelandic Prevention Model. Health Promot Pract. 2020 Jan;21(1):58-61.

In two decades, the Icelandic prevention model (IPM) has been employed to dramatically reduce rates of adolescent substance use in Iceland. Briefly, the IPM is a multisectoral, community-based, collaborative system where researchers, policy makers, administrative leaders, and practitioners join forces to reduce the odds of adolescent substance use over time. Comparatively, Iceland now ranks among the lowest in adolescent substance use in all of Europe. Since 2005, the IPM has garnered considerable international attention, and several countries or municipalities within them have adapted, or are presently adapting, the model to their needs. In this commentary, we first briefly review the history and formation of the IPM in Iceland from a school-based survey to a fully integrated prevention system.

Kristjansson AL, Mann MJ, Sigfusson J, Thorisdottir IE, Allegrante JP, Sigfusdottir ID (2020). Implementing the Icelandic Model for Preventing Adolescent Substance Use. Health Promot Pract. 2020 Jan;21(1):70-79.

This is the second in a two-part series of articles about the Icelandic Model for Primary Prevention of Substance Use (IPM) in this volume of Health Promotion Practice. IPM is a community collaborative approach that has demonstrated remarkable effectiveness in reducing substance use initiation among youth in Iceland over the past 20 years. While the first article focused attention on the background context, theoretical orientation, evaluation and evidence of effectiveness, and the five guiding principles of the model, this second article describes the 10 core steps to practical implementation.

Alfgeir L. Kristjanssona, John P. Allegrante, Jon Sigfusson, Inga Dora Sigfusdottir. Do population trends in adolescent electronic cigarette use coincide with
changes in prevalence of cigarette smoking? Preventive Medicine Reports 15 (2019).

Adolescents who initiate electronic cigarette (EC) use without having ever used tobacco are more likely than those that have not initiated EC use to try cigarette smoking over time. However, whether rates of EC use coincide with cigarette smoking rates at the population level remains unknown. This study aimed to compare trends in ever, current, and daily use of EC and cigarette smoking among adolescents in Iceland from 2015 to 2018.

James, J. E., Baldursdottir, B., Johannsdottir, K. R., Valdimarsdottir, H. B., & Sigfusdottir, I. D. (2018). Adolescent habitual caffeine consumption and hemodynamic James, J. E., Baldursdottir, B., Johannsdottir, K. R., Valdimarsdottir, H. B., & Sigfusdottir, I. D. (2018). Adolescent habitual caffeine consumption and hemodynamic creactivity during rest, psychosocial stress, and recovery. Journal of psychosomatic research, 110, 16-23.

This paper explores the relationship between caffeine consumption and cardiovascular health among adolescents; it hypothesized that compared to the consumption of little or no caffeine, adolescents who habitually consume caffeine have overall higher blood pressure and increased vascular resistance.

Vilhjalmsdottir, A., Bernburg, J. G., Gardarsdottir, R. B., & Sigfusdottir, I. D. (2018). Community income inequality and adolescent emotional problems: A population‐based study. Journal of Community Psychology.

This study contributes to the limited knowledge on the association between community income inequality and adolescent emotional problems, and explores whether these associations are contingent on national income inequality and personal deprivation. The results support the notion that the detrimental link between income inequality and adolescents’ emotional problems may be shaped by the level of income inequality in the larger societal context.

Kristjansson, A. L., Thomas, S., Lilly, C. L., Thorisdottir, I. E., Allegrante, J. P., & Sigfusdottir, I. D. (2018). Maternal smoking during pregnancy and academic achievement of offspring over time: A registry data-based cohort study. Preventive Medicine,113, 74-79.

This paper examines the relationship between maternal smoking during pregnancy (MSDP) and academic achievement among Icelandic youth. Results provide evidence of the persistent negative impact of MSDP on academic achievement in reactivity during rest, psychosocial stress, and recovery.

Sigfusdottir, I. D.; Kristjansson, A. L.; Thorlindsson, Th. & Allegrante, J. P. (2017). Stress and adolescent well-being: the need for an interdisciplinary framework. Health Promotion International, 32(6), 1081-1090.

This paper draws on several different but converging theoretical perspectives in an attempt to provide an overview of research relevant to stress in adolescence and puts forth a new framework that aims to provide both a common language and consilience by which future research can analyze the effects of multiple biological, social and environmental factors experienced during specific developmental periods, and cumulatively over time, on harmful behavior during adolescence. We present a framework to examine the effects of stress on diverse behavioral outcomes among adolescents, including substance use, suicidal behavior, self-inflicted harm, and delinquency.

Baldursdottir, B.; Taehtinen, R. E.; Sigfusdottir, I. D.; Krettek, A. & Valdimarsdottir, H. B. (2017). Impact of a physical activity intervention on adolescents subjective sleep quality: a pilot study. Global Health Promotion 1757-9759; Vol 24 (4): 14-22.

The aim of this pilot study was to examine the impact of a brief physical activity intervention on adolescents’ subjective sleep quality. Results indicated that brief physical activity interventions based on pedometers and step diaries may be effective in improving adolescents’ subjective sleep quality.

Kristjansson, A.L., Mann, M.J., Sigfusson, J., Sarbu, E.A., Grubliauskiene, J., Daily, S.M., Sigfusdottir, I.D. (2017). Prevalence of e-cigarette use among adolescents in 13 Eastern European Towns and Cities. Public Health, 147, 66 – 68.

This study provides data on the prevalence of EC use among adolescents in Eastern Europe. In this short report, we present findings on the prevalence of EC use among girls and boys in 13 Eastern European urban areas and the associations between EC use and CC smoking in that geographic region.

Sigfusdottir, I. D. Asgeirsdottir, B. B. Hall, H. A., Sigurdsson, J. F., Young S., Gudjonsson, G.H. (2017). An epidemiological study of ADHD and conduct disorder: does family conflict moderate the association? Social Psychiatry and Psychiatry Epidemiology, 52 (4), 457 – 464.

This paper aims to to examine the role of family conflict in the relationship between attention deficit hyperactivity disorder (ADHD) and conduct disorder (CD). The results of this study indicate that family environment and ADHD symptoms are important when predicting CD among adolescent youth.

Ragnarsdottir, L.D.; Kristjansson,A.L.; Thorisdottir, I.E; et al. (2017). Cumulative risk over the early life course and its relation to academic achievement in childhood and early adolescence. Preventive Medicine, 96, 36-41.

Early-life risk factors, such as family disruption, maltreatment, and poverty, can negatively impact children’s scholastic abilities; however, most previous studies have relied on cross-sectional designs and retrospective measurement. This study investigated the relation between cumulative risk factors during the early life course and subsequent academic achievement in a cohort of children and adolescents.

Baldursdottir, B.; Valdimarsdottir,H.B.; Krettek, A.; Gylfason, H.F., Sigfusdottir, I.D. (2017). Age-related differences in physical activity and depressive symptoms among 10-19-year-old adolescents: A population based study. Psychology of Sport and Exercise, 28, 91-99.

The aim of this study was to examine age- and gender-related patterns of PA and depressive symptoms among students through their adolescent years. Our findings show that the decrease in PA and increase in depressive symptoms is most pronounced around the transition from compulsory to upper-secondary school, or around the age of 15–16.

Mann, MJ., Kristjansson, AL., Smith, ML., Sigfusdottir, ID. (in press). The Influence of Negative Life Events and Problem Behavior on Grades in Early Adolescence: Pathways to Academic Risk in Middle School. Research in Middle Level Education.

Younger adolescents demonstrate a greater vulnerability to negative life events than do older adolescents and adults. The authors examined whether this heightened vulnerability includes a greater likelihood for participating in problem behaviors associated with poor academic outcomes and receiving lower grades.

Sigfusdottir, I. D.; Kristjansson, A. L.; Thorlindsson, Th. & Allegrante, J. P. Stress and adolescent well-being: the need for an interdisciplinary framework. Health Promotion International.

This paper draws on several different but converging theoretical perspectives in an attempt to provide an overview of research relevant to stress in adolescence and puts forth a new framework that aims to provide both a common language and consilience by which future research can analyze the effects of multiple biological, social and environmental factors experienced during specific developmental periods, and cumulatively over time, on harmful behavior during adolescence. We present a framework to examine the effects of stress on diverse behavioral outcomes among adolescents, including substance use, suicidal behavior, self-inflicted harm, and delinquency.

Kristjansson, AL; Sigfusdottir, ID; et al. Population trends in smoking, alcohol use and primary prevention variables among adolescents in Iceland. Addiction.

This paper aims to estimate linear time‐trends in substance use and primary prevention variables in adolescents in Iceland from 1997 to 2014. Results indicate that substance use among adolescents in Iceland has declined steadily from 1997 to 2014, while primary prevention factors for substance use have increased in strength during the same time‐period.

Gudjonsson, GH; Sigurdsson, JF; Sigfusdottir, ID; et al. A national epidemiological study investigating risk factors for police interrogation and false confession among juveniles and young persons. Social Psychiatric Epidemiology.

The principal aims of this study are to identify risk factors associated with police arrest and false confessions and to investigate whether the severity of the ADHD condition/symptoms increases the risk. The findings endorse the need for support of persons with ADHD to be put in place to ensure fair due process and to prevent miscarriages of justice.

Drake, KE; Sigfusdottir, ID; et al. Investigating the interplay between the reported witnessing and experiencing of physical violence within the home, the death of a parent or sibling, stress- sensitivity, and reported false confessions in males. Personality and Individual Differences.

This study investigates the interplay between the reported witnessing and experiencing of physical violence within the home, the death of a parent or sibling, latent stress-sensitivity levels, and reported false confessions in males.

Gudmundsdottir, DG; Asgeirsdottir, BB; Huppert, FA; Sigfusdottir, ID; et al. How Does the Economic Crisis Influence Adolescents’ Happiness? Population-Based Surveys in Iceland in 2000-2010. Journal of Happiness Studies.

The aim of this study was to explore the secular trend in happiness among Icelandic adolescents during a period of drastic change in the national economy as well as to identify which groups were most vulnerable and most resilient during the economic crisis. Emotional support from parents together with time spent with parents had the largest influence on adolescents’ happiness. An overall increase in time spent with parents was detected which might explain the increase in adolescents´ happiness over time. These results indicate that good relations with parents may protect adolescents from possible negative effect of a national economic crisis.  

Kristjansson, AL; Mann, MJ og Sigfusdottir, ID. Licit and illicit substance use by adolescent e- cigarette users compared with conventional cigarette smokers, dual users, and nonusers. Journal of Adolescent Health. Journal of Adolescent health

This paper aims to compare the lifetime prevalence of eight forms of substance use (alcohol, drunkenness, oral tobacco, snuff, sleeping pills/tranquilizers, sniffed glue, marijuana, and amphetamine) among adolescent e-cigarette (EC) users, conventional cigarette (CC) smokers, dual users, and nonusers. Smoking rates were similar for both sexes. The four groups assessed in this study appear to form a sequential risk gradient to the use of other substances.

Drake, KE; Sigfusdottir, ID; Sigurdsson, JF og Gudjonsson, GH. Gender differences in the interplay between exposure to trauma and parental disturbances within the home, stress-sensitivity and reported false confessions in adolescents. Personality and Individual Differences

The principal aim of this study is to investigate the interplay between the reported experience of physical/psychological trauma and disturbances involving parents within the home, latent stress-sensitivity, and the likelihood of reporting false confessions in females. This study has solidified the notion that a history of physical violence in particular at home may be a critical susceptibility factor amongst females. In males, self-report stress-sensitivity may be the critical susceptibility factor, both explaining the effect of physical/psychological trauma in the home on false confessions, and increasing sensitivity to exogenous interview pressure.

Álfgeir Logi Kristjánsson og Inga Dóra Sigfúsdóttir. E-cigarette use and relations to tobacco and alcohol use among adolescents. BMC Medicine.

This commentary focuses on two less discussed aspects of the EC debate: 1) whether EC use is likely to be additive to conventional cigarette and other tobacco use among minors, and 2) if EC use is likely to contribute to an overall increase in alcohol consumption and other drug use among minors. We conclude that EC use is likely to be additive to other tobacco use and increase the risk for alcohol use, therefore serving as another potential route to hazard for even mildly risk-prone minors.

Bryndís Björk Ásgeirsdóttir og Inga Dóra Sigfúsdóttir. Gender differences in co-occurrence of depressive and anger symptoms among adolescents in five Nordic countries. Scandinavian Journal of Public Health, 183-189.

The aim of this study was to carry out a comparative examination on gender differences in depressive and anger symptoms and their co-occurrence, using comparative self-report survey data from 16-19-year-old students in five Nordic countries.The results indicated that, on average, adolescent females reported higher levels of depressive symptoms than males in all the countries under study and higher levels of anger symptoms in four out of five countries.

Álfgeir Logi Kristjánsson, Michael J. Mann, Inga Dóra Sigfúsdóttir og Jack E. James. Mode of Daily Caffeine Consumption Among Adolescents and the Practice of Mixing Alcohol With Energy Drinks: Relationships to Drunkenness. Journal of Studies on Alcohol and Drugs, 397- 405.

In this study, we operationalized caffeine as daily consumption of coffee, tea, cola drinks, and energy drinks, and examined whether daily caffeine consumption relates to alcohol mixed with energy drinks (AmED) use and drunkenness. Caffeine use among adolescents ages 16–17 years is strongly related to increased consumption of AmED, irrespective of mode of caffeine consumption. AmED is strongly and positively associated with drunkenness on both individual and school levels.

Michael J. Mann, Álfgeir Logi Kristjánsson, Inga Dóra Sigfúsdóttir og Megan L. Smith. The Role of Community, Family, Peer, and School Factors in Group Bullying: Implications for School-Based Intervention. Journal of School Health, 477-486.

This study investigated community and family factors that influence school efforts to reduce odds of group bullying behavior and victimization. Parental support and time spent with parents were protective against group bullying behavior while worsening relationships with teachers and disliking school increased the likelihood of such behavior.

Kim E. Drake, Gísli H. Guðjónsson, Inga Dóra Sigfúsdóttir og Jón Friðrik Sigurðsson. An investigation into the relationship between the reported experience of negative life events, trait stress-sensitivity and false confessions among further education students in Iceland. Personality and Individual Differences, 135-140.

This study investigates the interplay between the reported experiences of negative life events, reported levels of nerves, fear and tension experienced over the past 30 days, and reported false confessions. A suggestion from the findings is that the type of false confession (the reason for it) may possibly dependent upon which contextual trigger has influenced the interviewee the most – those within the police interview itself and/or pressures from the wider environment within which they reside.

James, J. E., Kristjansson, A. L., & Sigfusdottir, I. D. (2015). A gender-specific analysis of adolescent dietary caffeine, alcohol consumption, anger, and violent behavior. Substance use & misuse, 50(2), 257-267.

Self-reported dietary caffeine and alcohol consumption were examined in relation to anger and violent behavior in Icelandic tenth-graders. Study findings suggest the need to take account of caffeine consumption in relation to adolescent anger and violence.

Mann, M. J., Kristjansson, A. L., Sigfusdottir, I. D. (in press). The Impact of Negative Life Events: Comparing the Relative Vulnerability of Middle School, High School, and College- age Students. Research in Middle Level Education Online.

Specifically, this paper examined young adolescents’ emotional vulnerability to NLEs and described how these vulnerabilities changed during adolescence, and we assessed the impact of event intensity, timing, and gender. This study makes an important contribution to the professional literature on readiness to learn in the middle grades by helping researchers and practitioners better understand how emotional vulnerability changes during adolescence and by discussing the implications of these changes for professional practice.

Eidsdottir, S. T., Kristjansson, A. L., Sigfusdottir, I. D., Garber, C. E., Allegrante, J. P. (in press). Association between higher BMI and depressive symptoms in Icelandic adolescents: the mediational function of body image. European Journal of Public Health.

The objective of this study was to examine the interplay between body mass index (BMI) and depressive symptoms, while accounting for the possible mediational role of body image, in a sample of older adolescents in Iceland. Results indicated that body image is a key contributor in the relationship between weight status and depressive symptoms among adolescents.

Kristjansson, A.L., Sigfusdottir, I.D., Sigfusson, J., Allegrante, J.P. (2014). Self-Generated Identification Codes in Longitudinal Prevention Research with Adolescents: A Pilot Study of Matched and Unmatched Subjects. Prevention Science, 15(2), 205-212.

Self-generated identification codes (SGICs) are an increasingly utilized methodological feature of longitudinal prevention research among adolescents. This study sought to test the differences between the matched and unmatched groups at baseline on a number of background, health, and well-being and risk behavior measures in a prevention study among 13- to 16-year-old Icelandic adolescents where a SGIC was constructed and used to link individual-level respondent data over two data collection points one year apart.

Kristjansson, A. L., Sigfusdottir, I. D., Mann, M. J., James, J. E. (2014). Caffeinated Sugar- Sweetened Beverages and Common Physical Complaints in Icelandic Children Aged 10-12 Years. Preventive Medicine, 58, 40-44.

Consumption of caffeinated sugar-sweetened beverages (CSSBs) among children and adolescents has increased markedly in recent years but the consequence of their consumption is not well understood. The objective of this study was to assess the prevalence of CSSBs in children aged 10–12 years and examine the relationship between CSSBs and common physical complaints.

Gudjonsson, G. H., Sigurdsson, J. F., Sigfusdottir, I. D., & Young, S. (2014). A national epidemiological study of offending and its relationship with ADHD symptoms and associated risk factors. Journal of Attention Disorders, 18(1), 3–13.

The objective was to disentangle the relationship between offending, ADHD, and comorbid risk factors. Findings indicated that the relationship between ADHD symptoms and offending among young people is largely explained indirectly by comorbid factors.

Sigfusdottir, I. D., Asgeirsdottir, B. B., Gudjonsson, G. H., & Sigurdsson, J. F. (2013). Suicidal ideations and attempts among adolescents subjected to childhood sexual abuse and family conflict/violence: The mediating role of anger and depressed mood. Journal of Adolescence, 36(6), 1227–1236.

Based on a sample of 9085 16- to 19-year-old students attending all high schools in Iceland in 2004, the current study examines depressed mood and anger as potential mediators between family conflict/violence and sexual abuse, on the one hand, and suicidal ideations and suicide attempts on the other. The authors discuss how these finding may inform and facilitate the design and development of interventions to reduce the likelihood of suicide attempts among young people.

Kristjansson, A. L., Sigfusdottir, I. D., & Allegrante, J. P. (2013). Adolescent substance use and peer use: a multilevel analysis of cross-sectional population data. Substance abuse treatment, prevention, and policy, 8(1), 27.

This study sought to add to a growing body of literature into peer contexts by testing a model of peer substance use simultaneously on individual and school community levels while taking account of several well established individual level factors. The school-level findings in this study represent context effects that are over and above individual-level associations.

Kristjansson, A.L., Sigfusson, J., Sigfusdottir, I.D., Allegrante, J.P. (2013). Data collection procedures for school-based surveys among adolescents: the Youth in Europe Study. Journal of School Health, 83(9), 662-667.

This article builds on a 15‐year long experience of such annual data collections in Iceland and describes the preparation, process, and collection of data that provide a common methodologic framework for the school‐based survey, Youth in Europe, a population‐based survey of 14‐ to 16‐year‐old adolescents, being collected across 18 European cities now participating in the European Cities Against Drugs (ECAD) program.

Kristjansson, A. L., Sigfusdottir, I.D., Frost, S.S., & James, J.E. (2013). Adolescent Caffeine Consumption and Self-reported Violence and Conduct Disorder. Journal of Youth and Adolescence, 1 – 10.

We investigate the relationship between adolescent caffeine use and self-reported violent behaviors and conduct disorders in a population-based cross-sectional sample of 3,747 10th grade students (15–16 years of age, 50.2 % girls) who were enrolled in the Icelandic national education system during February 2012. Through a series of multiple regression models, while controlling for background factors, Attention Deficit Hyperactivity Disorder symptoms and current medication and peer delinquency, and including measures on substance use, our findings show robust additive explanatory power of caffeine for both violent behaviors and conduct disorders.

Eidsdottir, S.T., Kristjansson, A.L., Sigfusdottir, I.D., Garber, C.E., Allegrante, JP. (2013). Secular trends in overweight and obesity among Icelandic adolescents: Do parental education levels and family structure play a part? Scandinavian Journal of Public Health, 41, 384-391.

To investigate whether the secular trend in the increasing prevalence of overweight and obesity among 16- to 20-year-old adolescents in Iceland varied by levels of parental education and family structure. Findings indicated that differences in parental levels of education are associated with accelerating trends in prevalence of overweight and obesity among 16- to 20-year-old adolescents in Iceland.

Yang, F., Helgason, A.R., Sigfusdottir, I.D., Kristjansson, A.L. (2013). Electronic Screen Use and Mental Well-being of 10-12 year old children. European Journal of Public Health, 23(3), 492-498.

This study sought to identify (i) the magnitude of total daily electronic screen time and (ii) the relations between electronic screen use and mental well-being indicators, in a sample of 10–12-year-old children. This study is the first of its kind to demonstrate a dose-response relationship between electronic screen use and mental well-being in 10–12-year-old children. Further research is needed to assess the validity and potential implications of these findings.

Sigfusdottir, I.D., Kristjansson, A.L., Agnew, R. (2012). A Comparative Analysis of General Strain Theory. Journal of Criminal Justice, 40, 117-127.

Since its introduction in 1992, general strain theory (GST) has garnered much empirical support. This study tests GST in five different cities across Europe: Bucharest in Romania, Sofia in Bulgaria, Riga in Latvia, Kaunas in Lithuania and Reykjavik in Iceland.

Gísladóttir ,T.L, Matthíasdóttir, A., Kristjánsdóttir, H. (2013). The effect of adolescents’ sports clubs participation on self-reported mental and physical conditions and future expectations. J Sports Sci, 31(10), 1139-45.

This study investigates the relationship between adolescents’ sports clubs participation and self-reported mental and physical conditions and future expectations. The results indicate that participation in sports clubs influences adolescents positively; adolescents who work hard at sport not only believe they are in better mental and physical condition, they also believe they can succeed in other areas such as their studies.

Asgeirsdottir, BB., Ingolfsdottir, G., & Sigfusdottir, ID. (2012). Body Image Trends among Icelandic Adolescents: A Cross-sectional National Study from 1997 to 2010. Body Image, 9, 404-408.

The aim of this study was to evaluate trends in body image among Icelandic adolescents from 1997 to 2010. The results are encouraging and indicate that in an age of increased overweight and obesity, the body image of Icelandic adolescents is becoming more positive.

Guðjonsson, GH., Sigurdsson, JF., Sigfusdottir, ID., et al. (2012). False confessions to police and their relationship with conduct disorder, ADHD, and life adversity. Personality and Individual Differences 52, 696-701.

Attention deficit hyperactivity (ADHD) symptoms and life adversity have been associated with the reporting of false confessions to crime, but it is not known if these predict false confessions beyond conduct disorder. The findings suggest that suspects’ resilience to resist pressure from police and peers is weakened by their condition rather than their false confession representing irresponsible and delinquent behaviour associated with conduct disorder.

Sigfusdottir, ID., Kristjansson, AL., Robert, A. (2012).  A comparative analysis of general strain theory. Journal of Criminal Justice 40, 117-127.

Since its introduction in 1992, general strain theory (GST) has garnered much empirical support. This study tests GST in five different cities across Europe: Bucharest in Romania, Sofia in Bulgaria, Riga in Latvia, Kaunas in Lithuania and Reykjavik in Iceland.

Guðjonsson, GH., Sigurdsson, JF., Sigfusdottir, ID., et al. (2012).  An epidemiological Study of ADHD symptoms among young persons and the relationship with cigarette smoking, alcohol consumption, and illicit drug use. Journal of Child Psychology and Psychiatry 53, 304-312.

This study investigates the relationship between attention deficit hyperactivity disorder (ADHD) symptoms and cigarette smoking, alcohol use and illicit drug use. The findings underscore the vulnerability of young persons with ADHD symptoms to smoking, alcohol and illicit drug use, possibly as a means of self‐medication, and emphasize a need for early identification and treatment to reduce the risk of escalation.

Thorisdottir, IE., Kristjansson, AL., Sigfusdottir, ID., et al. (2012). The landscape of Overweight and Obesity in Icelandic Adolescents: Geographic Variation in Body-Mass Index between 2000 and 2009. Journal of Community Health 37, 234-241.       

The prevalence of overweight and obesity has increased globally. This study examined the geographic variation in overweight and obesity trends among Icelandic adolescents in urban and rural areas.

Palsdottir, A., Asgeirsdottir, B. B., & Sigfusdottir, I. D. (2012). Gender difference in well-being during school lessons among 10 to 12 year old children: The effects of school, family and peer related factors. Scandinavian Journal of Public Health, 40, 605-613.

The aim of the study was to examine gender difference in self-reported wellbeing during school lessons among Icelandic 10–12-year-old boys and girls, in grades 5–7 in elementary schools. Also, to examine whether factors related to attitudes towards school subjects, student–teacher relationships and student–peer relationships mediated the associations between gender and wellbeing during school lessons.   

Gunnlaugsson, G., Kristjansson, AL., et al. (2011). Intrafamilial conflict and emotional well-being: A population based study among Icelandic adolescents. Child Abuse & Neglect 35, 372-381.

The present study has two main objectives: (1) ascertain a national base rate of intrafamilial conflicts and physical violence at home among Icelandic adolescents; and (2) to investigate the association of witnessing and/or having been a part of intrafamilial conflict or physical violence at home with variables that relate to mental health and well-being.

James, JE., Kristjansson, AL., Sigfusdottir, ID., et al. (2011).  Adolescent substance use, sleep, and academic achievement: Evidence of harm due to caffeine. Journal of Adolescence 34, 665-673.

Using academic achievement as the key outcome variable, 7377 Icelandic adolescents were surveyed for cigarette smoking, alcohol use, daytime sleepiness, caffeine use, and potential confounders. Findings suggest the importance of including measurements of caffeine consumption in future studies of adolescent substance use.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP & James, JE. (2011). Adolescent Caffeine Consumption, Daytime Sleepiness, and Anger. Journal of Caffeine Research 1 (1), 75-82.

With self-reported anger as the key outcome variable, 7348 Icelandic adolescents were surveyed for caffeine consumption, cigarette smoking, alcohol use, daytime sleepiness, and potential confounders. High prevalence of daily caffeine consumption and the strength of the observed associations between caffeine and other important biobehavioral and psychosocial variables demonstrate the importance of including measurements of caffeine consumption in future studies of adolescent adjustment and development.

Sigfusdottir, ID., Asgeirsdottir, BB., Sigurdsson, JF., Gudjonsson, GH. (2011). Physical activity buffers the effects of family conflict on depressed mood: A study on adolescent girls and boys.  Journal of Adolescence 34, 895-902

This paper investigates the relationship between physical activity and depressed mood, under conditions of family conflict.The findings highlight the role of physical activity in decreasing mental distress among adolescents, especially those living in aversive circumstances at home.

Kristjansson, AL., Sigfusdottir, ID., Karlsson, T., Allegrante, JP. (2011). The Perceived Parental Support (PPS) Scale: Validity and reliability in the 2006 Youth in Europe substance use prevention survey. Child Indicators Research 4 (3), 515-528.

Parental support has been shown to reduce mental distress among adolescents; however, it is not known whether perceived parental support is a valid and reliable construct across culture. Using data from 23,605 14- to 15-year-olds across eight European cities we assessed the validity and reliability of the Perceived Parental Support (PPS) Scale.

Asgeirsdottir, BB., Sigfusdottir, ID., Gudjonsson, GH. et al. (2011).  Associations between sexual abuse and family conflict/violence, self-injurious behavior, and substance use: The mediating role of depressed mood and anger Child Abuse & Neglect 35, 210-219.

This paper examined whether depressed mood and anger mediate the effects of sexual abuse and family conflict/violence on self-injurious behavior and substance use.These results indicate that in cases of sexual abuse and family conflict/violence, substance use is similar to externalizing behavior, where anger seems to be a key mediating variable, opposed to internalizing behavior such as self-injurious behavior, where depressed mood is a more critical mediator.

James, JE., Kristjansson, AL., Sigfusdottir, ID. (2011). Adolescent Substance Use, Sleep, and Academic Achievement: Evidence of Harm Due to Caffeine. Journal of Adolescence 34, 665-673

Using academic achievement as the key outcome variable, 7377 Icelandic adolescents were surveyed for cigarette smoking, alcohol use, daytime sleepiness, caffeine use, and potential confounders. Findings suggest the importance of including measurements of caffeine consumption in future studies of adolescent substance use.

Asgeirsdottir BB, Gudjonsson GH, Sigurdsson JF, et al. (2010). Protective processes for depressed mood and anger among sexually abused adolescents: The importance of self-esteem. Personality and individual differences, 49 (5), 402-407.

The aim of the study was to investigate the protective processes for depressed mood and anger among sexually abused adolescents. These results underscore the specific importance of self-esteem when predicting depressed mood and anger among sexually abused adolescents. They also indicate that parental support, attitudes towards school and sport participation are important predictors of these emotional problems, both directly and indirectly through their effects on self-esteem.

Kristjansson, AL., James, JE., Allegrante, JP., Sigfusdottir, ID., Helgason, AR. (2010). Adolescent substance use, parental monitoring, and leisure time activities: 12-year outcomes of primary prevention in Iceland. Preventive Medicine, 51, 168-171.

This paper aimed to examine 12-year changes in alcohol use and cigarette smoking in response to community-based prevention activities among Icelandic adolescents. Results found that parental monitoring and adolescent participation in organized sports increased in communities that adopted the intervention program compared to communities that did not, whereas unmonitored idle hours and attendance at unsupervised parties decreased.

Eidsdottir, SP, Kristjansson, AL., Sigfusdottir, ID, Garber, CE, Allegrante, JP. (2010).Trends in Body Mass Index among Icelandic Adolescents and Young Adults from 1992 to 2007. International Journal of Environmental Research and Public Health, 7, 2191-2207.

Trends in body mass index (BMI) among 51,889 14- to 20-year-old Icelandic adolescents and young adults were examined using data from cross-sectional population surveys conducted from 1992 to 2007. Moreover, not only has the prevalence of obesity increased, but also the extent of obesity has grown more severe among 15- and 17-year-olds boys and among girls in the oldest age group.

Sigurdsson, JF., Gudjonsson, G., Asgeirsdottir, BB., Sigfusdottir, ID. (2010) Sexually abusive youth: what are the background factors that distinguish them from other youth? Psychology, Crime and Law, 16 (4), 289-303.

The purpose of this article is to investigate the background of young sexual perpetrators within the framework of the Beech and Ward’s (Aggression and Violent Behaviour, 10, 31–63, 2004) etiological model of risk. The findings emphasize the importance of sexual abuse, poor self-regulation, and the potential influence of peers in sexual offending.

Sigfusdottir, ID, Gudjonsson, GH, Sigurdsson, JF. 2010. Bullying and delinquency: The mediating role of anger. Personality and Individual Differences, 48, 391-396.

The principal aim of the study was to examine the relationship between bullying, both studying those who bully and those who are victims of bullying, and non-violent delinquency (i.e., theft and burglary).The findings support Agnew’s revised general strain theory that emotions such as anger are important in delinquency.

Kristjansson, AL., Sigfusdottir, ID., James, JE., Allegrante, JP., Helgason, AR. (2010).

Perceived Parental Reactions and Peer Respect as Predictors of Adolescent Cigarette Smoking and Alcohol Use. Addictive Behaviors, 35, 256-259.

This study examined the importance of perceived parental reactions to, and peer respect for, cigarette smoking and alcohol use. Particular attention was given to the relative importance of these variables compared with the more widely examined influences of perceived parental and peer support. Our findings indicate that perceived parental reaction to use and peer respect for use may be important contributors to adolescent cigarette smoking and alcohol use.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP. (2010). Health Behavior and Academic Achievement among Adolescents: The Relative Contribution of Dietary Habits, Physical Activity, BMI and Self-Esteem. Health Education & Behavior, 37(1), 51-64.

This study tested a structural equation model to estimate the relationship between health behaviors, body mass index (BMI), and self-esteem and the academic achievement of adolescents. In contrast, poor dietary habits negatively influenced self-esteem and academic achievement, and self-esteem was negatively influenced by increasing levels of BMI (β = –.05).

Thorlindsson, Th. Halldorsson, V. (2010). Sport, and use of anabolic androgenic steroids among Icelandic high school students: a critical test of three perspectives. Substance Abuse Treatment Prevention and Policy, 5, 32.

This study investigates the use of anabolic androgenic steroids (AAS) among a nation

Asgeirsdottir BB, Gudjonsson GH, Sigurdsson JF, et al. (2010). Protective processes for depressed mood and anger among sexually abused adolescents: The importance of self-esteem. Personality and individual differences, 49 (5), 402-407.

The aim of the study was to investigate the protective processes for depressed mood and anger among sexually abused adolescents. These results underscore the specific importance of self-esteem when predicting depressed mood and anger among sexually abused adolescents. They also indicate that parental support, attitudes towards school and sport participation are important predictors of these emotional problems, both directly and indirectly through their effects on self-esteem.

Kristjansson, AL., James, JE., Allegrante, JP., Sigfusdottir, ID., Helgason, AR. (2010). Adolescent substance use, parental monitoring, and leisure time activities: 12-year outcomes of primary prevention in Iceland. Preventive Medicine, 51, 168-171.

This paper aimed to examine 12-year changes in alcohol use and cigarette smoking in response to community-based prevention activities among Icelandic adolescents. Results found that parental monitoring and adolescent participation in organized sports increased in communities that adopted the intervention program compared to communities that did not, whereas unmonitored idle hours and attendance at unsupervised parties decreased.

Eidsdottir, SP, Kristjansson, AL., Sigfusdottir, ID, Garber, CE, Allegrante, JP. (2010).Trends in Body Mass Index among Icelandic Adolescents and Young Adults from 1992 to 2007. International Journal of Environmental Research and Public Health, 7, 2191-2207.

Trends in body mass index (BMI) among 51,889 14- to 20-year-old Icelandic adolescents and young adults were examined using data from cross-sectional population surveys conducted from 1992 to 2007. Moreover, not only has the prevalence of obesity increased, but also the extent of obesity has grown more severe among 15- and 17-year-olds boys and among girls in the oldest age group.

Sigurdsson, JF., Gudjonsson, G., Asgeirsdottir, BB., Sigfusdottir, ID. (2010) Sexually abusive youth: what are the background factors that distinguish them from other youth? Psychology, Crime and Law, 16 (4), 289-303.

The purpose of this article is to investigate the background of young sexual perpetrators within the framework of the Beech and Ward’s (Aggression and Violent Behaviour, 10, 31–63, 2004) etiological model of risk. The findings emphasize the importance of sexual abuse, poor self-regulation, and the potential influence of peers in sexual offending.

Sigfusdottir, ID, Gudjonsson, GH, Sigurdsson, JF. 2010. Bullying and delinquency: The mediating role of anger. Personality and Individual Differences, 48, 391-396.

The principal aim of the study was to examine the relationship between bullying, both studying those who bully and those who are victims of bullying, and non-violent delinquency (i.e., theft and burglary).The findings support Agnew’s revised general strain theory that emotions such as anger are important in delinquency.

Kristjansson, AL., Sigfusdottir, ID., James, JE., Allegrante, JP., Helgason, AR. (2010). Perceived Parental Reactions and Peer Respect as Predictors of Adolescent Cigarette Smoking and Alcohol Use. Addictive Behaviors, 35, 256-259.

This study examined the importance of perceived parental reactions to, and peer respect for, cigarette smoking and alcohol use. Particular attention was given to the relative importance of these variables compared with the more widely examined influences of perceived parental and peer support. Our findings indicate that perceived parental reaction to use and peer respect for use may be important contributors to adolescent cigarette smoking and alcohol use.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP. (2010). Health Behavior and Academic Achievement among Adolescents: The Relative Contribution of Dietary Habits, Physical Activity, BMI and Self-Esteem. Health Education & Behavior, 37(1), 51-64.

This study tested a structural equation model to estimate the relationship between health behaviors, body mass index (BMI), and self-esteem and the academic achievement of adolescents. In contrast, poor dietary habits negatively influenced self-esteem and academic achievement, and self-esteem was negatively influenced by increasing levels of BMI (β = –.05).

Thorlindsson, Th. Halldorsson, V. (2010). Sport, and use of anabolic androgenic steroids among Icelandic high school students: a critical test of three perspectives. Substance Abuse Treatment Prevention and Policy, 5, 32.

This study investigates the use of anabolic androgenic steroids (AAS) among a national representative sample of high school students in Iceland. Our findings suggest that the use of AAS and especially illegal substances should be considered more as a social and a health problem rather than a sport specific issue.

Gudjonsson, G., Sigurdsson, JF, Sigfusdottir, ID (2009). False confessions among 15- and 16-year-olds in compulsory education and the relationship with adverse life events. Journal of Forensic Psychiatry & Psychology, 20(6), 950-963.

This study investigates the relationship between false confession during interrogation and background life adversity. The findings suggest that major life adversity leaves young persons vulnerable to giving a false confession when arrested and questioned by police as a suspect.

Gault-Sherman, M., Silver, E., Sigfusdottir, ID (2009). Gender and the associated impairments of childhood sexual abuse: A national study of Icelandic youth. Social Science and Medicine, 69, 1515-1522.

The current study used a national probability sample of 8618 Icelandic youth between the ages of 16 and 20 to examine the impairments associated with childhood sexual abuse for male and female victims. Overall, our results suggest that gender differences in impairment may depend on the particular outcome measured.

Gudjonsson, GH., Sigurdsson, JF, Sigfusdottir, ID. (2009). Interrogation and false confessions among adolescents in seven European countries: What background and psychological variables best discriminate between false confessors and non-false confessors? Psychology, Crime & Law, 15, 711-728.

The main aim of the study was to investigate the rate of claimed false confession during police questioning and identify variables that best discriminate between false confessors and non-false confessors. The study shows the importance of history of victimization and substance misuse among adolescents in relation to giving a false confession to police during interrogation.

Kristjansson, AL., Sigfusdottir, ID. (2009). The Role of Parental Support, Parental Monitoring, and Time spent with Parents on Adolescent Academic Achievement in Iceland: A Structural Model of Gender Differences. Scandinavian Journal of Educational Research, 53, 481-496.

Bernburg, JG., Thorlindsson, T., Sigfusdottir, ID (2009). The neighborhood effects of disrupted family processes on adolescent substance use. Social Science & Medicine, 69, 129-137.

In the current paper, we argue that the neighborhood-level of disrupted family processes (weak social ties to parents and coercive family interaction) should have a contextual effect on adolescent substance use (cigarette smoking, heavy drinking, and lifetime cannabis use), because adolescents living in neighborhoods in which disrupted family processes are prevalent should be more likely to associate with deviant (substance using) peers.

Sigfusdottir, ID, Silver, E. (2009). Emotional Reactions to Stress among Adolescent Boys and Girls: An Examination of the Mediating Mechanisms proposed by General Strain Theory. Youth and Society, 40, 571-590.

This study examines the effects of negative life events on anger and depressed mood among a sample of 7,758 Icelandic adolescents, measured as part of the National Survey of Icelandic Adolescents (Thorlindsson, Sigfusdottir, Bernburg, & Halldorsson, 1998).These results raise questions about the role of anger and depressed mood in explaining gender differences in stress-related delinquent behavior.

Bernburg, JG., Thorlindsson, Th., Sigfusdottir, ID. (2009). Relative Deprivation and Adolescent Outcomes in Iceland: A Multilevel Test. Social Forces, 87, 1223-1250.

The theory of relative deprivation emphasizes that social comparisons contextualize how people experience impoverishment. An important application of this theory argues that relative deprivation that stems from unfavorable social comparisons can result in anger, normlessness and an increased likelihood of deviant behavior.

Bernburg, JG., Thorlindsson, Th., Sigfusdottir, ID. (2009). The spreading of suicidal behavior: The contextual effect of community household poverty on adolescent suicidal behavior and the mediating role of suicide suggestion. Social Science & Medicine, 68, 380-389.

The current study examines the contextual effect of community household poverty on adolescent suicidal behavior (suicide ideation and suicide attempt). The study demonstrates how the concentration of individual problems can have macrolevel implications, creating social mechanisms that cannot be reduced to the circumstances or characteristics of individuals.

Sigfusdottir, ID., Thorlindsson, Th., Kristjansson, AL., Roe, KM., Allegrante, JP. (2009). Substance use prevention for adolescents: the Icelandic Model. Health Promotion International, 24(1), 16-25.

This paper describes the development, implementation and results of the Icelandic Model of Adolescent Substance Use Prevention. The Icelandic Model is a theoretically grounded, evidence-based approach to community adolescent substance use prevention that has grown out of collaboration between policy makers, behavioural scientists, field-based practitioners and community residents in Iceland.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP., Helgason, AR. (2009). Parental divorce and adolescent cigarette smoking and alcohol use: assessing the importance of family conflict. Acta Pædiatrica, 98, 537-542.

This paper aims to investigate how family conflict contributes to the relationship between parental divorce and adolescent cigarette smoking and alcohol use. Findings indicate that family conflicts are important contributors to the relationship between parental divorce and adolescent cigarette smoking and alcohol use. Conflict between parents and adolescents, but not inter-parental conflict, appears to be the most important factor in the relationship between family conflict and adolescent substance use.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP., Helgason, AR. (2009).  Adolescent Health Behavior, Contentment in School, and Academic Achievement. American Journal of Health Behavior, 33(1), 69-79.

Thorlindsson, Th. Bernburg, JG. (2009). Community structural instability, anomie, imitation and adolescent suicidal behavior. Journal of Adolescence 32(2), 233-245.

This paper aimed to examine the association between health behavior indicators, school contentment, and academic achievement. Findings may inform the efforts to improve academic achievement and the general health status of youth.

Sigfusdottir, ID., Kristjansson, AL., Thorlindsson, Th., Allegrante, J.P. (2008). Trends in prevalence of substance use among Icelandic adolescents, 1995–2006.  Substance Abuse Treatment, Prevention, and Policy, 3, 12.

The aim of this study was to examine trends in prevalence of daily smoking, alcohol intoxication, and illicit substance use among Icelandic adolescents.The decline in prevalence of adolescent substance use in Iceland is plausibly the result of local community collaboration where researchers, policy makers and practitioners who work with young people have combined their efforts.

Gudjonsson, GH., Sigurdsson, JF, Sigfusdottir, ID, Asgeirsdottir, BB. (2008). False confessions and individual differences: The importance of victimization among youth. Personality and Individual Differences, 45, 801-805.

The principal aim of the study was to investigate the relationship between false confession during custodial interrogation and history of victimization among young persons. The findings provide strong evidence of the relationship between being a victim of bullying and giving false confessions.

Sigfusdottir, ID., Asgeirsdottir, BB., Sigurdsson, JF. and Gudjonsson, GH. (2008). Trends in depressive symptoms, anxiety symptoms and visits to healthcare specialists:  A national study among Icelandic adolescents. Scandinavian Journal of Public Health, 36(4), 361 – 368.

The aim of the study was to examine trends in adolescent depression and anxiety symptoms from 1997 to 2006, using four time-points (1997, 2000, 2003, and 2006), and adolescent mental health service use in the same period, using three time-points (1997, 2000, and 2006).The findings show that symptoms of depression and anxiety have increased among adolescents in Iceland. Future work would benefit from further research into the trends in risk and protective factors associated with these outcomes. The findings call particular attention to the increasing risk for depression and anxiety symptoms among girls.

Sigfusdottir, ID., Asgeirsdottir, BB., Gudjonsson, GH., Sigurdsson, JF. (2008). A Model of Sexual Abuse´s effects on Suicidal Behavior and Delinquency: The Role of Emotions as Mediating Factors. Journal of Youth and Adolescence, 37, 699–712.

Drawing on Agnew’s general strain theory, we examined whether depressed mood and anger mediated the effects of sexual abuse on suicidal behavior and delinquency. Participants included 9,113 students attending high schools in Iceland. These findings highlight the complex nature of the effects of strain on adolescents’ emotions and behavior.

Kristjansson, AL., Sigfusdottir, ID., Allegrante, JP., Helgason, AR. (2008). Social correlates of cigarette smoking among Icelandic adolescents: A population-based cross-sectional study. BMC Public Health, 8, 86.

To better understand the social mechanisms that influence adolescent smoking, we analyzed the relationship and relative importance of a broad spectrum of social variables in adolescent smoking in Iceland, a Nordic country with high per-capita income.We conclude that multiple social factors are related to adolescent smoking. Parents and other primary preventive agents need to be informed about the complicated nature of the adolescent social world in order to maximize their impact.

Eidsdottir, SÞ., Kristjansson, AL., Sigufsdottir, ID. et al. (2008). Trends in physical activity and participation in sports clubs among Icelandic adolescents. European Journal of Public Health 18(3), 289-293.

We examined trends in physical activity and participation in sports clubs among Icelandic adolescents. Although our results show an overall increase in vigorous physical activity and participation in sports clubs over the past decade among both genders, our data also indicate that over half of all Icelandic adolescents are not achieving the recommended level of participation in physical activity.

Kristjansson, AL. (2007). On Social Equality and Perceptions of Insecurity. European Journal of Criminology, 4(1), 59–86.

This study compares perceptions of insecurity and fear of crime in Scotland and Iceland and shows how these perceptions are related to social factors in the two countries. The analysis suggests that perceptions of insecurity are higher in Scotland than in Iceland because Iceland’s population is more homogeneous, with stronger social integration, less pronounced class and income differentials, and less polarization between neighbourhoods. The wider implications for understanding perceptions of insecurity at different levels of analysis (macro and meso) are discussed.

Gudjonsson, GH., Sigurdsson, JF., Asgeirsdottir, BB., Sigfusdottir, ID. (2007). Custodial interrogation: What are the background factors associated with claims of false confession to police? The Journal of Forensic Psychiatry & Psychology, 18(2), 266 – 275. Sigfusdottir, ID., Kristjansson, AL. and Allegrante, JP. (2007). Health behaviour and academic achievement in Icelandic school children. Health education research, 22(1), 70-80.

Interest in the relationship between health behaviours and academic achievement has recently intensified in the face of an epidemic of childhood and adolescent obesity and converging school reforms in the United States and other nations with advanced economies. We analysed cross-sectional survey data from 5810 Icelandic school children to explore the relationship between selected health behaviours and academic achievement.

Gunnlaugsson, GG, Kristjansson, AL, Einarsdottir, J, Sigfusdottir, ID. (2007). Domestic conflict, emotional well- being and delinquent behaviour: a population-based study among Icelandic adolescents. European Journal of Public Health, 17, suppl.2, 97. Sigfusdottir, ID., Thorlindsson, Th. and Bjarnason, Th. (2007). Religion: soutien divin et tension psychologique [Religion: Divine Support and psychological tension] Social Compass, 54, 473.

The authors investigate the relationship between religion and delinquent behaviour, under conditions of strain. The study shows that both structural support, measured as religious participation and functional support, measured as perceived support from one’s God, hinder delinquency. Divine support, however, does not condition the effects of strain on the outcome variable.

Thorlindsson, Th., Bjarnason, Th. and Sigfusdottir, ID. (2007). Individual and Community Processes of Social Closure:  A Study of Adolescent Academic Achievement and Alcohol Use. Acta Sociologica, 50, 161 – 168.

While the concept of social capital has rekindled interest in fundamental issues of social inquiry, concerns have been raised regarding its definition and application in increasingly diverse topics. We address these concerns by revisiting Coleman’s and Bourdieu’s original ideas of the role of family and school in adolescent outcomes. The results support the general thrust of social capital theory and suggest further theoretical elaborations.

Sigfusdottir, ID., Gudjonsson, GH., Sigurdsson, JF., Asgeirsdottir, BB., Sigfusdottir, ID. (2006). Custodial interrogation, false confession and individual differences: A national study among Icelandic youth. Personality and Individual Differences, 41, 49–59.

The main aims of the study were twofold. Firstly, to ascertain a national base rate of custodial interrogation, confession, denial and false confession among Icelandic youth (age group 16–24 years), and secondly, to investigate psychological and criminological factors associated with false confession.A Discriminant Function Analysis found that false confessions during interrogation were mostly associated with the extent of involvement in delinquent activities, the involvement of friends in delinquency, and depression.

Bjarnason, Th., Thorlindsson, Th., Sigfusdottir, ID., Welch, MR. (2005). Familial and Religious Influences on Adolescent Alcohol Use: A Multi-Level Study of Students and School Communities. Social Forces, 84(1), 375-390.

A multi-level Durkheimian theory of familial and religious influences on adolescent alcohol use is developed and tested with hierarchical linear modeling of data from Icelandic schools and students. The religiosity of individual parents is not significantly related to their children’s alcohol use, but female students drink significantly less in schools where religious parents are more prevalent. The results are generally consistent with the proposed theoretical model.

Sigfusdottir, ID., Farkas, G. and Silver, E. (2004). The Role of Depressed Mood and Anger in the Relationship Between Family Conflict and Delinquent Behavior. Journal of Youth and Adolescence, 33(6), 509-522.

This paper examines whether depressed mood and anger mediate the effects of family conflict on delinquency. We use structural equation modeling to show that exposure to arguments and fights at home are positively related to both depressed mood and anger among adolescents. Anger is positively associated with delinquent behavior whereas depressed mood has no effect on delinquency.

Bjarnason, Th. and Sigfusdottir, ID. (2002). Nordic Impact: Article Productivity and Citation Patterns in Sixteen Nordic Sociology Departments.Acta Sociologica, 45, 253-267.

This paper focuses on journal articles produced by current (as of 1 January 2001) faculty of 16 of these Nordic Sociology departments in the period 1981-2000. First, xve proride a brief overview of article productivity and citations to articles produced in this period by country and department. Second. we estimate a multilevel model of citation patterns by articles published. the academic position and productivity of each author, and the structure and protluctirity of each department as a whole. Third. we test the extent to which the effects of such factors differ between departments and individuals. The findings strongly suggest that diversity is a defining characteristic of this sociological community, precluding monolithic definitions of Nordic sociology.