Developmental trajectories of conduct problems and time-varying peer problems: the Bergen child study.

BACKGROUND: While it is increasingly acknowledged that conduct problems and peer problems often co-occur in development, less is known about the ways in which peer problems may alter the developmental course of conduct problems for distinct subgroups. METHODS: Using data from a large population-based study in Norway (the Bergen Child Study/youth@hordaland; 47.4% males), we estimated group-based trajectories of conduct problems and the presence of time-varying peer problems on the developmental progression of conduct problems between seven and 19 years of age. Risk factors for group membership were also examined. RESULTS: A 3-group model of conduct problems best fit the data (non-engagers, low-engagers, moderate-stable). The presence of peer problems increased the estimated level of conduct problems for both the low-engagers and moderate-stable groups across adolescence. No differences in conduct problems were observed when peer problems were present in childhood or preadolescence for these two groups, nor for the non-engagers group at any point. Being male, having lower perceived economic wellbeing, and lower levels of parental education predicted group membership for the moderate-stable group, whilst lower paternal education predicted membership for the low-engagers group. CONCLUSIONS: Support for developmental 'turning points' was found, suggesting that adolescence is a particularly salient time for those with conduct problems. In particular, the presence of peer problems can increase observed conduct problems at this stage in development.

Prospective associations between adolescent risky substance use and school dropout and the role of externalising and internalising problems.

Background: The aim of the present study was to assess to what extent risky substance use (RSU) acts as an important risk factor for school dropout from upper secondary school in a prospective study of Norwegian adolescents, and how externalising and internalising mental health problems influenced this association. Methods: We used data from a large population-based survey (the youth@hordaland-survey), which included adolescents aged 16-19 years. The predictor variables were self-reported RSU. The survey was linked with prospective data from the Norwegian Education Database, following the adolescents to 21-23 years of age. The outcome variable was registry-based school dropout within five years after starting upper secondary school. The analyses were adjusted for sex, age, socioeconomic status, and externalising and internalising problems. Results: After adjustment for sociodemographic variables, all indicators of RSU were prospectively associated with school dropout (adjusted odds ratios 1.26-2.25; all p values <.01). While internalising problems only slightly changed these estimates, the associations were substantially attenuated by externalising problems. Still, all measures of RSU, except frequent alcohol intoxication, remained positively associated with school dropout in the fully adjusted models. For the youngest students, all associations between RSU and school dropout were significant. Conclusions: Adolescent RSU is a strong predictor for school dropout, and externalising problems explained a considerable proportion of this effect. Prevention efforts to reduce student substance could improve academic outcomes among upper secondary school students, and such efforts may benefit from also targeting co-occurring externalising problems.

Parental unemployment and educational outcomes in late adolescence: the importance of family cohesion, parental education, and family income in a Norwegian study.

AIMS: The study aimed to investigate the association between parental unemployment and grade point average and school completion in adolescence, and the importance of family cohesion, parental education, and family income in explaining these associations. METHODS: Data stem from the Norwegian cross-sectional 2012 youth@hordaland-survey including 8437 adolescents (53.4% girls). Information on grade point average, school completion, parental education, and family income were retrieved from the National Education Database. Parental work status and family cohesion were assessed by adolescent self-report. RESULTS: Adolescents with at least one unemployed parent had lower grade point averages (3.49 compared with 3.92, P<0.001) and rates of school completion (71.9% compared with 86.6%, P<0.001) compared with adolescents with two working parents. The associations between parental unemployment and both grade point average (b = -0.22, 95% confidence interval -0.32, -0.12) and school completion (odds ratio 0.59, 95% confidence interval 0.46, 0.76) partly attenuated but remained significant when taking family cohesion, parental education, and family income into account. There was a significant interaction between parental unemployment and family cohesion on grade point average, in which the positive association between family cohesion and grade point average was weaker for adolescents with unemployed parents. CONCLUSIONS: Adolescents with parents outside of the workforce are at higher risk of poorer educational outcomes than peers with working parents. Combined with the positive associations between parental education, family cohesion, family income, and educational outcomes, this underscores the importance of parents for adolescent educational outcomes, and suggests that parents and the family situation should be considered when providing academic support for adolescents who struggle in upper secondary school.

Protective factors associated with resilience among unaccompanied refugee minors after settling in Norway: a matched cross-sectional study.

This study aimed to examine protective factors associated with resilience among unaccompanied refugee minors in comparison to their Norwegian peers and to examine associations between resilience factors and characteristics related to positive outcomes among unaccompanied minors. Data stem from the Pathways to Independence study conducted in Bergen municipality, Norway in 2018-2019 where 81 unaccompanied minors aged 15-20 participated (83.3% male; 80% response rate). An age- and sex-matched control group of 324 adolescents was retrieved from the youth@hordaland study conducted in Norway in 2012. Resilience factors were assessed by the Resilience Scale for Adolescents. Unaccompanied minors reported lower scores on Goal Orientation (d = 0.4), Social Competence (d = 0.4), and Social Support (d = 0.7) compared to Norwegian adolescents. Being male was associated with lower scores on Goal Orientation (standardized mean difference [SMD] = - 0.9) and Social Support (SMD = - 0.9) among unaccompanied minors, while being in frequent contact with family in the home country was associated with higher scores on all resilience factors (SMD range = 0.6-1.1). The number of leisure activities was associated with Social Competence (SMD = 0.22). There were no significant associations between the resilience factors and amount of support in the living arrangements or contact with the child welfare services. Unaccompanied minors reported fewer resilience factors compared to Norwegian adolescents, indicating that they may have different needs compared to other adolescents. Our study also suggests that frequent contact with family in the home country may be important to bolster positive development for unaccompanied minors after settlement.

Mental health problems and suicidal behavior from adolescence to young adulthood in college: linking two population-based studies.

It is well established that mental health problems are highly recurrent and persistent from childhood to adolescence, but less is known to what extent mental health problems also persist from adolescence into young adulthood. The aim of the current study was therefore to examine the chronicity and risk of mental health problems and suicidality from adolescence to young adulthood. Data stem from two Norwegian population-based studies conducted 6 years apart; the youth@hordaland study from 2012 (age 16-19) and the SHoT2018 study (age 22-25). These two data sources were linked to produce a longitudinal sample of 1257 individuals. A wide range of self-reported mental health and suicidality instruments (used both continuously and categorically) were analyzed using log-link binomial regression analysis, adjusting for age, sex, parental education, and financial problems. We found that high levels of mental health problems in late adolescence were a significant risk factor for reporting poor mental health 6 years later. Internalizing and externalizing problems in adolescence were associated with a 2.8-fold and 1.9-fold increased risk, respectively, of reporting a mental disorder 6 years later. Similarly, self-harm in adolescence was associated with a 2.1-fold increased risk of suicidal thoughts 6 years later. The magnitudes of the adjusted risk ratios were generally similar across the various mental health and suicidality measures used at the two assessment points. Adjustment for confounders did not, or only slightly, attenuate the risk ratios, and all associations remained statistically significant in the adjusted analyses. This longitudinal study provides new evidence of the chronicity of mental health problems and suicidality from adolescence to adulthood in Norway. The results emphasize the importance of early identification and timely interventions to reduce the prevalence and impact of mental health problems and suicidality.

Using Norwegian National Patient Registry data to understand associations between potentially traumatic life experiences and mental health care use in adolescence.

Exposure to potentially traumatic experiences (PTEs) is common among children and adolescents and associated with an increased risk of psychiatric diagnoses. This study aimed to ascertain how the number of PTEs differed across adolescent psychiatric diagnoses. Data on PTE exposure were derived from the youth@hordaland survey, and Axis 1 data were from the linked Norwegian National Patient Registry (NPR). Among 10,257 total adolescents, 9,555 (age range: 16-19 years, 53.9% female) consented to register linkage, 8,845 of whom were included in the analyses. Having contact with Child and Adolescent Mental Health Services (CAMHS) predicted more PTEs (estimated marginal mean [EMM] = 1.04, SE = 0.05) and exposure to two or more PTEs compared to having no CAMHS contact (EMM = 0.60) after adjusting for age, ethnicity, sex, and parental education. Adolescents diagnosed with attention-deficit/hyperactivity disorder, depression, trauma-related disorders, conduct disorder, and anxiety experienced significantly more PTEs (EMMs = 0.90-1.63) than those with no CAMHS contact (EMM = 0.57, SE = 0.01). All diagnostic categories except psychosis, autism spectrum disorders, and eating disorders had a significantly higher rate of PTEs compared with adolescents with no CAMHS contact. The study highlights the potential role of exposure to multiple PTEs as a transdiagnostic risk factor, although the level of risk varies between diagnoses.

Sleep and dropout from upper secondary school: A register-linked study.

OBJECTIVE: The present study investigates the association between sleep in late adolescence and completion of upper secondary school. METHODS: The data are drawn from the youth@hordaland study, a large population-based study conducted in 2012, linked with official educational data in Norway (N = 8838). RESULTS: High school dropout was more prevalent among adolescents who had insomnia (20.6%) compared to those without insomnia (14.3%; adjusted risk ratios = 1.50; 95% confidence intervals: [2.19-2.92]). There was also a higher rate of school dropout among those who had symptoms of delayed sleep-wake phase (21%) compared to those without delayed sleep-wake phase (14.3%); adjusted risk ratios = 1.43, 95% confidence intervals: (1.28-1.59). School noncompleters were also characterized by reporting 44 minutes shorter sleep duration, longer sleep onset latency, and wake after sleep onset (both approx. 15 minutes) compared to school completers. CONCLUSION: The importance of sleep for high school dropout rates highlights the importance of including sleep as a risk indicator and a possible target for preventive interventions in late adolescence.

Negative Life Events, Protective Factors, and Substance-Related Problems: A Study of Resilience in Adolescence.

BACKGROUND: There is compelling evidence for an association between negative life events (NLE) and substance-related problems (SRP) during adolescence. The literature is, however, still limited with regards to protective factors for SRP among adolescents exposed to NLE. METHODS: A large population-based survey including 9,611 Norwegian adolescents aged 16 to 19 years, comprised the dataset of this study. The main explanatory variable was NLE. The main outcome variable was SRP, assessed by the CRAFFT scale. Potential protective factors were measured with five subscales from the Resilience Scale for Adolescents (READ) questionnaire. The potential protective factors and sex were explored as moderators for the associations between NLE and SRP. RESULTS: NLE were strongly associated with SRP. Four out of five potential protective factors (i.e., Goal Orientation, Self-confidence, Family Cohesion, and Social Support) showed evidence of a protective-stabilizing effect. Even if they had protective effect across all levels of exposure to NLE, these effects were even stronger for adolescents with high exposure. For Family Cohesion a protective-stabilizing effect was only evident for boys, while a direct protective effect was found for girls. Finally, Social Competence was the only factor that did not show any evidence of promoting resilience toward SRP. CONCLUSIONS: NLE had a strong relation with SRP in this study. Protective factors buffered against SRP for all adolescents - but particularly so for adolescents who had high exposure to NLE. These findings highlight the need for preventive efforts to strengthen protective factors that may promote resilience among adolescents at risk for SRP.

Joint physical custody and academic achievement among youth: A population-based study with registry linkage.

Previous research has documented that youth in joint physical custody (JPC) often report fewer mental health problems than peers in other postseparation living arrangements. Whether JPC is associated with functional outcomes such as academic achievement has been less examined, and existing work has relied on self-reported school grades and pertinent controls such as parental education. Using data from the Norwegian population-based youth@hordaland study (n = 7,914), we examined the association between living arrangements and academic achievement among youth (16-19 years) using register-based information on grade point average (GPA; range: 1-6), parental education, and income. We also assessed the influence of family cohesion and coresiding biological and half/stepsiblings in explaining differences between youth in JPC and other living arrangements. Across all regression models, youth in JPC had significantly higher GPA (0.2-0.4 points) than youth living with a single mother or father. Parental education had a strong attenuating effect and reduced the magnitude of the difference with 30%-35% for youth in single-parent families and 55% for youth in stepparent families. In conclusion, we find that youth in JPC have a small but significant academic advantage compared to peers in single-parent families, which is not fully accounted for by objective measures of parental education and income, sibling composition, and family cohesion. Future longitudinal studies are needed to disentangle whether positive outcomes associated with JPC are due to inherent qualities of this living arrangement or better captured by preseparation selection mechanisms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Substance-Related Problems in Adolescents with ADHD-Diagnoses: The Importance of Self-Reported Conduct Problems.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a known risk factor for substance-related problems (SRP) during adolescence, but the nature of this relationship and the importance of co-occurring conduct problems are not fully understood. METHODS: Data stem from a linked dataset between a large population-based survey conducted in 2012 of Norwegian adolescents aged 16 to 19, and registry-based data from specialized child and adolescent mental health services (n = 9,411). RESULTS: Adolescents with "ADHD + high conduct problems" had increased risk of SRP (odds ratios = 2.37-10.14). Adolescents with "ADHD only" had very similar risk of SRP as adolescents from the general population with low symptoms of conduct problems. Relative to boys, girls with "ADHD + high conduct problems" appeared to have somewhat higher risk for SRP. CONCLUSION: The present study suggests that the risk for SRP among adolescent with ADHD is largely driven by co-existing conduct problems.

Sleep patterns and insomnia among adolescents receiving child welfare services: A population-based study.

OBJECTIVES: Sleep problems are common in adolescence. We aimed to investigate sleep patterns and insomnia in Norwegian adolescents who have been in contact with child welfare services (CWS), both adolescents living in foster care (FC) and adolescents receiving in-home-services (IHS). Both groups were compared to youth who reported they were not receiving child welfare interventions. DESIGN: Cross-sectional. SETTING: The population-based study youth@hordaland from 2012 in Hordaland, Norway. PARTICIPANTS: About 9421 adolescents (53.8% girls), age range 16-19 years, were divided into 3 groups; IHS group (n = 123), FC group (n = 132), and control group (n = 9166). MEASUREMENTS: Self-reported information about demographics, detailed sleep patterns, sleep problems, and adverse life events. RESULTS: Adolescents receiving IHS (vs. controls) had significantly shorter sleep duration, lower sleep efficiency, longer sleep onset latency (SOL), wake after sleep onset (WASO), and higher prevalence of insomnia. They had increased odds of insomnia (adjusted odds ratio [AOR] = 1.77, 95% confidence interval [CI] = 1.19-2.62) and SOL ≥ 30 minutes (AOR = 1.95, CI = 1.32-2.87). Adolescents in FC (vs. controls) reported lower sleep efficiency and longer WASO. When adjusting for sex and age, the associations did not substantially change. When additionally adjusting for adverse life events, the associations were considerably attenuated for both groups, and were no longer significant for the FC group. CONCLUSION: Our results indicate a higher rate of sleep problems among adolescents receiving interventions from CWS, particularly those receiving IHS. Adverse life events accounted for a substantial part of the increased risk of sleep problems.

Smoking and snus use among Norwegian students: Demographic, personality and substance use characteristics.

Background and aim: Smoking rates are decreasing in Norway while the use of snus has increased. We aimed to investigate the co-occurrence of, and the socio-demographics, personality and substance use characteristics associated with, student smoking and snus use. Methods: Survey data were collected among students in higher education in Bergen, Norway in 2015 (N = 11,236, response rate 39.4%). Multinomial regression analyses comparing snus users and smokers to non-users and non-smokers, respectively, on demographic, personality and substance use variables were conducted. Regression analyses comparing current dual users to current smokers and current snus users and comparing daily smokers to daily snus users, on demographic, personality and substance use variables were also conducted. Results: In total 67.9% of ever snus users identified themselves as non-smokers (past and current). Several demographic, personality and substance use characteristics associated with smoking and snus use were identified (all = p < .05), some of which were common for both (e.g., use of cannabis) and some which were exclusively associated with either smoking (e.g., neuroticism) or snus use (e.g., extroversion). Conclusion: The current study contributes with several novel findings regarding traits associated with smoking and snus use. Though limited by a cross-sectional design, the current findings may suggest that the group of students using snus consists of a combination of previous smokers, students who would have smoked if snus was not available and a new segment who may not have used nicotine if snus was not available.

Bullying Involvement in Adolescence: Implications for Sleep, Mental Health, and Academic Outcomes.

Adolescents' involvement in bullying is associated with both sleep and mental health problems, but the nature of this association remains unclear; further, its association with academic outcomes has received little attention. Thus, the aims of the current study were to (a) determine whether involvement in bullying as a victim, bully, or bully-victim was associated with greater sleep and mental health problems and (b) explore the potential mediating effect of sleep and mental health problems on the association between bullying and academic outcomes. A large 2012 population-based study in Hordaland County, Norway, surveyed 10,220 adolescents (16-19 years; 54% girls) about bullying involvement using the revised version of the Olweus Bully/Victim Questionnaire, detailed sleep assessment, and mental health questionnaires. Academic outcomes were obtained from official administrative registries. 1.7% of the adolescents (n = 156) reported being victims of bullying, 1.0% (n = 92) reported being a bully, and 0.5% (n = 50) reported being a bully-victim. All categories of bullying involvement had higher rates of mental health problems compared with adolescents not involved in bullying. Victims reported more symptoms of anxiety and depression, whereas bullies reported higher rates of conduct problems. Adolescents in all bullying categories also reported significantly shorter sleep duration and higher prevalence of insomnia as well as lower grade point average (GPA) compared with adolescents not involved; however, school absence was not associated with bullying involvement. Bullying involvement and GPA showed complete mediation for bullies and bully-victims and partial mediation for victims through sleep duration, conduct problems, and symptoms of depression and attention deficit hyperactivity disorder (ADHD). Bullying is strongly associated with mental health and sleep problems, in addition to lower academic performance. Findings support the importance of addressing bullying involvement during this important developmental period.

Life events and adolescent depressive symptoms: Protective factors associated with resilience.

INTRODUCTION: Depression is a public health concern among youth, and it is pertinent to identify factors that can help prevent development of depressive symptoms in adolescence. This study aimed to investigate the association between negative life events and depressive symptoms among adolescents, and to examine the influence and relative contributions of personal, social and family protective factors related to resilience. METHODS: Data stem from the cross-sectional youth@hordaland-survey, conducted in Hordaland, Norway. In all, 9,546 adolescents, aged 16-19 years old (52.8% girls) provided self-report information on depressive symptoms, negative life events and protective factors related to resilience. RESULTS: Experiencing a higher number of negative life events was related to increases in depressive symptoms, while the potential protective factors goal orientation, self-confidence, social competence, social support, and family cohesion individually were associated with fewer symptoms. Although there were small moderating effects of goal orientation and self-confidence, the results mainly supported a compensatory resilience model. When considering the potential protective factors jointly, only self-confidence and family cohesion were significantly associated with fewer depressive symptoms for both genders, with the addition of social support for girls. There were significant interactions between all the potential protective factors and gender, indicating a greater reduction of depressive symptoms with higher levels of protective factors among girls. CONCLUSIONS: Interventions aimed at fostering self-confidence and family cohesion could be effective in preventing depressive symptoms for adolescent boys and girls, regardless of their exposure to negative events. Results further indicate that preventive interventions targeting these potential protective factors could be especially beneficial for adolescent girls.

Sleep patterns and insomnia among internationally adopted adolescents.

OBJECTIVE: Sleep is essential for adolescent development. We aimed to investigate sleep patterns and insomnia among internationally adopted adolescents compared with their nonadopted peers. DESIGN: Cross-sectional. SETTING: Data stem from the population-based youth@hordaland-survey, conducted during winter/spring 2012, in Hordaland, Norway. PARTICIPANTS: Of the 9846 adolescents who responded to the sleep measures in the youth@hordaland-survey, 44 were identified as international adoptees by linkage to the Central Adoption Registry. MEASURES: The adolescents provided self-report information on demographic characteristics, mental health problems, and a range of sleep measures. RESULTS: There were no significant differences between the adoptees and nonadopted peers regarding how much time they spent in bed, but the internationally adopted adolescents reported significantly shorter sleep duration, both on weekdays (d=0.37, P = .014) and weekends (d=0.37, P = .015). The difference was due to the adoptees spending longer time awake after sleep onset (d=0.78, P > .001). Furthermore, 32% of the adopted adolescents fulfilled the DMS-5 criteria for insomnia, compared with 18% of their nonadopted peers (odds ratio 2.06, 95% CI: 1.09-3.90). However, this association was no longer significant after adjusting for symptoms of depression. Adolescents adopted after 12 months of age reported more sleep problems than those who were adopted earlier. CONCLUSION: The short sleep duration and high occurrence of insomnia among the internationally adopted adolescents suggest both a problem area that should receive more focus and a potential avenue for intervention. The results further suggest that assessing both mental health problems and sleep problems among internationally adopted adolescents who are experiencing difficulties could help target interventions.

Divorce and adolescent academic achievement: Heterogeneity in the associations by parental education.

BACKGROUND: The link between parental divorce and adolescents' academic achievement may depend on parental educational levels. However, findings have been inconsistent regarding whether the negative associations between parental divorce and adolescents' academic outcomes are greater or smaller in highly educated families. The present study aimed to investigate the possible heterogeneity in the associations between divorce and adolescents' academic achievement by parental educational levels, within the context of the elaborate Norwegian welfare state. METHODS: The population-based cross-sectional youth@hordaland study of adolescents aged 16-19 years conducted in Norway in 2012, provided information about parental divorce and was linked to national administrative registries (N = 9,166) to obtain high-quality, objective data on the adolescents' grade point average (GPA), and their parents' educational qualifications and income. RESULTS: The negative association between parental divorce and GPA was stronger among adolescents with educated or highly educated parents compared to adolescents with less educated parents. This heterogeneity was driven by maternal educational qualifications, whereby divorce was more strongly and negatively associated with GPA among adolescents with educated mothers compared to those with less educated mothers, independent of paternal educational levels and income measures. CONCLUSIONS: Among adolescents whose parents have low educational qualifications, parental divorce is not associated with their academic achievement. Educated divorced mothers appear less likely to transfer their educational advantages onto their children than nondivorced equally educated mothers, perhaps due to a "double-burden" regarding work pressure and child-rearing responsibilities. There is a need for future studies to detail the mechanisms underlying this finding.

Factor Structure and Psychometric Properties of the Resilience Scale for Adolescents (READ).

Psychometric evaluations of the Resilience Scale for Adolescents (READ) have yielded inconsistent support for the original five-factor solution, with different modifications being proposed. The aim of the present article was to investigate the psychometric properties and factor structure of the READ using both confirmatory and exploratory methods, and to evaluate how the scale fits within the theoretical framework of resilience. Data stem from the population-based youth@hordaland-study of 9,596 adolescents from 16 to 19 years of age. Using confirmatory factor analysis, the original five-factor model yielded relatively poor fit. A better model fit was identified for a different five-factor structure using exploratory methods including two new personal factors measuring (a) Goal Orientation and (b) Self-Confidence. This division was supported by low secondary loadings and moderate correlations between the factors, and gender differences in the mean scores. Although the READ is a multidimensional measure that includes individual, family, and social factors related to the resilience process, some important aspects of resilience have not been included.

Alcohol consumption, life satisfaction and mental health among Norwegian college and university students.

OBJECTIVE: High-level alcohol consumption is common in, and central to, the student community. Among adults, high-level alcohol consumption, and sometimes also low, has been associated with poorer social integration and mental health. We aimed to investigate how alcohol consumption relates to life satisfaction and mental health among students in higher education. METHODS: Data from the Norwegian study of students' health and well-being (SHoT, 2014, n = 9632) were used. Associations between alcohol consumption (AUDIT; abstainers, low risk, risky and hazardous consumption) and life satisfaction and mental health complaints, as well as number of close friends, and social and emotional loneliness were investigated using linear regression models. Crude models and models adjusted for age, gender and relationship status were conducted. RESULTS: Students reporting hazardous consumption reported lower life satisfaction, more mental health complaints, and more emotional and social loneliness than students with low risk consumption. Students reporting risky consumption reported slightly reduced life satisfaction and more mental health complaints, but more close friends and less social loneliness. Abstainers did not report reduced life satisfaction or more mental health complaints, despite reporting fewer close friends and more social loneliness. CONCLUSION: High-level alcohol consumption among students might indicate increased risk of several problems in the future - but also currently. Our findings further imply that the quality of friendships might be more important for life satisfaction and mental health than the number of friends, but also that social integration in student communities might be more difficult for students who do not drink.

Alcohol and drug use among internationally adopted adolescents: Results from a Norwegian population-based study.

Internationally adopted adolescents are at increased risk for mental health problems. However, little is known about problematic alcohol and drug use, which are important indicators of maladjustment. The aim of this study was to examine the level of problematic alcohol and drug use in internationally adopted adolescents compared to their nonadopted peers. The study is based on data from the youth@hordaland-survey, which was conducted in Hordaland County, Norway, in the spring of 2012. All adolescents born from 1993 to 1995 residing in Hordaland at the time of the study were invited to participate. Information on adoption was obtained from the Central Adoption Registry and linked to self-report data from the youth@hordaland-survey. Among 10,200 participants, 45 were identified as internationally adopted. No significant differences were found between international adoptees and their peers regarding whether or not they had tried alcohol or illicit drugs or their patterns of drinking behavior. However, adopted adolescents had a higher mean score on a measure of problematic alcohol and drug use compared to their nonadopted peers. The difference was attenuated and no longer significant when adjusting for measures of depression and attention-deficit/hyperactivity disorder. Results from a structural equation model indicated a full mediation effect of mental health problems on the association between adoption status and problematic alcohol and drug use. Our findings indicate that internationally adopted adolescents experience more problematic alcohol and drug use than their nonadopted peers, and the difference can largely be explained by mental health problems. (PsycINFO Database Record