Encouraging greater empowerment for adolescents in consent procedures in social science research and policy projects.

The United Nations Convention on the Rights of the Child emphasizes the importance of allowing children and adolescents to influence decisions that are important to them following their age and maturity. This paper explores the principles, practices, and implications around using parental versus child/adolescent consent when participating in social science research and policy development. Experiences from two studies are presented: The Confronting Obesity: Co-creating policy with youth (CO-CREATE) and the Health Behaviour in School-aged Children (HBSC) study, a World Health Organization (WHO) Collaborative Cross-National study. Although parental consent may be an important gatekeeper for protecting children and adolescents from potentially harmful research participation, it may also be considered an obstacle to the empowerment of children and adolescents in case they want to share their views and experiences directly. This paper argues that evaluation of possible harm should be left to ethics committees and that, if no harm related to the research participation processes is identified and the project has a clear perspective on collaborating with the target group, adolescents from the age of 12 years should be granted the legal capacity to give consent to participate in the research project. Collaboration with adolescents in the development of the research project is encouraged.

Psychometric Evaluation of the Swedish Acceptance and Action Diabetes Questionnaire: A Rasch Analysis.

Background and purpose: The Acceptance and Action Diabetes Questionnaire (AADQ) is a tool for assessing the acceptance of thoughts and emotions related to diabetes in people living with the disease. This study aimed to examine the psychometric properties of the Swedish version of AADQ (Swe-AADQ) in a sample of adults with type 1 diabetes. Methods: To examine the psychometric properties of the Swe-AADQ, the Rasch model was used. Data for 120 individuals were included. Results: The Swe-AADQ showed an acceptable fit to the Rasch model. A sufficiently high value of the separation index indicated a capacity to distinguish between different levels of acceptance in the sample. The seven-point Likert scale was reduced to three categories suggesting an improvement in the ordering of the item thresholds. Conclusions: The Swe-AADQ possesses reasonable quality in terms of reliability and validity. However, there are some deficiencies regarding the categorization of the response rating that should be addressed.

Relationship between Eczema and Self-reported Difficulties Keeping up with School Education: A Cross-sectional Study.

Eczema is a common chronic disease that affects both children and adults, and may have an adverse impact on school performance, as it is characteristically pruritic, and hence may lead to poor concentration and inadequate sleep. The aim of this study was to elucidate the relationship between eczema and self-reported difficulties keeping up with school education. The study was based on cross-sectional questionnaire data collected in schools among all 9th graders (15-16 years old) within a Swedish county. Logistic regression analyses were used to assess the association between having eczema and self-reported difficulties keeping up with school education. A total of 2,620 pupils participated (50.1% female). An increased odds ratio (OR) of self-reported difficulties keeping up with school education was found in adolescents with eczema compared with those without eczema after adjustment for sex and  family residence (OR 2.13, 95% confidence interval (95% CI) 1.32-3.44), and with additional adjustment for sleeping problems, attention-deficit hyperactivity disorder, allergy, rhinitis, asthma, and alcohol consumption (adjusted OR 1.78, CI 1.05-3.00). Eczema may be a relevant risk factor for difficulty keeping up with school education in adolescents. However, studies that can assess temporality, based in different settings with objective reports of both eczema and self-reported difficulties at school, are needed to confirm these findings.

Worry and Psychosomatic Problems Among Adolescents in Sweden in the Wake of the COVID-19 Pandemic: Unequal Patterns Among Sociodemographic Groups?

PURPOSE: To analyze potential associations between sociodemographic factors and adolescents' worry about family finances and other types of worries during the COVID-19 pandemic and the potential associations between different worry themes and psychosomatic problems. METHODS: From December 2020 to March 2021, 3,068 16-17 years old students in Sweden completed a questionnaire about the impact of the COVID-19 pandemic on their schooling and everyday life. From April to June 2020, 70% of these students also responded to questions about their psychosomatic health. Logistic regression was applied to analyze the associations between sociodemographic factors and different worry themes and estimate the association between worry and psychosomatic problems. RESULTS: Across all 13 worry themes, girls reported worry to a higher degree than boys. In most of the cases, adolescents with a lower parental educational background or immigrant background reported more frequent worrying. This was most evident for worry about family finances. The differences between adolescents with a Swedish background and those with a foreign background were large except for worry about climate change. All worry themes were associated with the students' psychosomatic health. Those who often or always experienced worry were more likely to report psychosomatic problems. Worry about family finances showed the highest odds ratio and marginal effect. DISCUSSION: Worry about family finances during the COVID-19 pandemic turns out to be a strong and socially structured stressor that may widen the health inequalities among young people. This underlines the need for preventive and promoting measures aimed at supporting socioeconomic disadvantaged groups.

How do children and adolescents of separated parents sleep? An investigation of custody arrangements, sleep habits, sleep problems, and sleep duration in Sweden.

OBJECTIVES: An increasing number of children and adolescents divide their time between their separated parents' homes. Although marital conflict is disadvantageous for children's sleep, little is known about how children of separated parents sleep. The objective was to investigate the association between children's custody arrangements and sleep habits and sleep initiation difficulties. DESIGN: Cross sectional nationally representative samples of adolescents from the WHO study Health Behaviour in School-aged Children (HBSC) (n = 11,802). SETTING: Sweden in 2013/2014 and 2017/2018. PARTICIPANTS: Adolescents in grades 5, 7, and 9 from Swedish compulsory comprehensive school. MEASUREMENTS: The survey included questions on sleep behaviors including bedtime, wake-up time and frequency of sleep onset problems. The analysis methods used were ordinary least squares and logistic regression. RESULTS: The results show differences by custody arrangement, but they are not uniform across the dependent variables. Children and adolescents in sole maternal custody were less likely to sleep as much as recommended (P < .001), more likely to have late bedtimes (P < .001), report sleep initiation difficulties (P < .01) and to report social jetlag between school mornings and weekends (P < .05) compared to those in 2-parent families. Shared physical custody was associated with a higher likelihood of late bedtimes (P < .05) and sleep initiation difficulties (P < .05) compared to those in 2-parent families, but not of sleeping less than recommended or reporting social jetlag. Less-than-equal sharing was generally associated with worse sleep than in 2-parent families. CONCLUSIONS: As custody arrangements seem to be associated with sleep, it is important to understand the mechanisms behind the findings.

Electronic media use and symptoms of depression among adolescents in Norway.

BACKGROUND: The purpose of this study was to examine the association between electronic media use, including use of social media and gaming, and symptoms of depression, and whether gender or having friends moderated these associations. METHODS: This study was based on self-reported cross-sectional data from the Ungdata survey, conducted in 2018 by the Norwegian Social Research (NOVA) Institute in cooperation with seven regional drug and alcohol competence centres. The target group comprised 12,353 15-16 years old adolescents. Binominal logistic regression was used to analyse the association between electronic media use and symptoms of depression. RESULTS: The odds of having symptoms of depression were higher for those who used social media more than 3 hours per day (OR: 1.60, 95% CI: 1.43-1.80), compared to those who used social media 3 hours or less per day. Additionally, the odds of having symptoms of depression was higher for those who used more than 3 hours on gaming per day (OR: 1.57, 95% CI: 1.36-1.80), compared to those who used 3 hours and less on gaming per day after adjustment for potential confounders. There were no interaction effects between social media and gaming use with symptoms of depression. Neither were the associations between social media use and gaming with symptoms of depression moderated by gender or having friends. CONCLUSIONS: The odds of having symptoms of depression were significantly higher for adolescents with a more frequent use of electronic media.

The association between screen time and reported depressive symptoms among adolescents in Sweden.

BACKGROUND: How screen use is associated with adolescents' mental health has been widely debated in public media during the last decade, but there is still lack of information about if and how the associations vary between types of electronic media. OBJECTIVE: This study aimed to examine how time spent on types of screen use (social media, gaming alone, gaming in groups and watching TV) was associated with depressive symptoms among adolescents in Sweden, and whether gender moderated these associations. METHODS: We analysed data from the Swedish section of the Children of Immigrants: Longitudinal Survey in Four European Countries. The final sample consisted of 3556 eighth grade adolescents in 2011 (51% girls). We used logistic regression analysis to estimate the odds ratio of feeling depressed often versus less often/not at all using time spent on different types of screen use as predictor variables. Additionally, we tested interaction effects between gender and the predictor variables. RESULTS: Our results showed that spending more than 2 hours on social media was associated with higher odds of feeling depressed often compared with spending 2 hours or less. Not watching TV was associated with higher odds of feeling depressed often compared with watching TV. These patterns did not differ across genders. Gaming alone and gaming in groups were not associated with depressive symptoms. CONCLUSIONS: Our findings suggest that more frequent social media use and not watching TV were associated with a higher level of depressive symptoms.

This study examined how time spent on four types of screen use including social media, gaming alone, gaming in groups and watching TV was associated with depressive symptoms among adolescents in Sweden, and whether these associations differed for girls and boys. We analysed data from the Swedish section of the Children of Immigrants: Longitudinal Survey in Four European Countries. The final sample consisted of 3556 eighth grade adolescents in 2011 (51% girls). We used logistic regression analysis to estimate the odds ratio of feeling depressed often versus less often/not at all using time spent on different types of screen use as predictor variables. In addition, we tested interaction effects between gender and the predictor variables. Our results showed that social media use and not watching TV was associated with higher odds of feeling depressed often. Gaming alone and gaming in groups were not associated with higher level of depressive symptoms. These patterns did not differ across genders.

Improvements in the school environment-results of a Swedish school project 2005-2011.

To examine whether a public health project to reduce problem behavior in schools and improve the classroom climate, undertaken among eight secondary schools in a municipality in Sweden, was accompanied by favorable changes in the school environment over time. Data were collected from ninth grade students (aged 15-16 years) at three different time points: the year before the project began (2005), during the project (2008) and when the project finished (2011). Changes in the school environment, measured as damage, littering, noise and classroom disorder, were compared between the project municipality and a comparison group of other municipalities in the same county, using multinomial logistic regression analysis. Descriptive comparisons were made between the schools within the project municipality. The school environment improved significantly from 2005 to 2011 in the project municipality compared with the other municipalities. The school environment was improved in all schools within the project municipality. The biggest improvements took place in two schools which systematically worked with one program incorporated into the school schedule. This study demonstrates that it may be possible to improve the school environment by implementing health programs. Further studies based on experimental designs are required in order to confirm the potential and efficiency of school health programs.

Leisure time physical activity and depressive symptoms among adolescents in Sweden.

BACKGROUND: Mental health problems have increased noticeably among adolescents. Physical activity has been identified as an important factor in the promotion of mental health. The purpose of this study was to explore how leisure time physical activity was associated with depressive symptoms among adolescents in Sweden. METHODS: Using binary logistic regression we analyzed Swedish data collected as part of the Children of Immigrants: Longitudinal Survey in Four European Countries. The complete sample used for analysis consisted of 3787 adolescents (including 1855 boys and 1932 girls). RESULTS: Adolescents who participated in physical activity during their leisure time on a daily, weekly, or monthly basis had substantially lower odds of often feeling depressed than those who were physically inactive. This pattern applied to both boys and girls. Relative to boys, girls had significantly higher odds of often feeling depressed. CONCLUSIONS: The findings of this study suggested that participation in physical activity regularly during leisure time was associated with a lower level of depressive symptoms among adolescents in Sweden. Because of the cross-sectional study design conclusions about causality cannot be drawn. Future research based on longitudinal data is needed to further explore the mechanisms behind the association. This study calls for recognition of the value of physical activity in promoting mental health among adolescents.

Classroom Disorder and Internalizing Problems Among Swedish Adolescents: Changes Between 1988 and 2011.

BACKGROUND: Internalizing problems have increased among Swedish adolescents. We examined whether classroom disorder was associated with internalizing problems and whether it explained the trends in internalizing problems. Furthermore, we examined whether school contextual factors were associated with internalizing problems and whether they moderated the association between classroom disorder and internalizing problems. METHODS: We used repeated cross-sectional survey data (1988-2011) among all 15- to 16-year-old students in Värmland, Sweden (N = 9491 boys, N = 9313 girls). School-level factors were the proportions of students with a low/average socioeconomic or an immigration background. RESULTS: Results from mixed effects models showed that classroom disorder was associated with internalizing problems across the years of investigation but did not explain the trends in internalizing problems. This association was moderated by the school-level proportion of students with a low/average socioeconomic background but not the school-level proportion of students with an immigration background. CONCLUSIONS: Students who perceived their classroom to be disorderly more often also reported more internalizing problems. Future studies are necessary to investigate other potential school factors that may explain the trends in internalizing problems.

Gender and secular trends in adolescent mental health over 24 years - The role of school-related stress.

Increasing levels of psychosomatic symptoms, and other mental health problems, among adolescents, and especially among girls, have been reported across various countries. The "educational stressors hypothesis" states that this trend can be explained by an increasing amount of stressors in the school environment. This study tests this hypothesis, using repeated cross-sectional data, between the years 1993-2017, from the Health Behaviours of School-aged Children (HBSC) survey. Regression and decomposition techniques are used to investigate the role of school stress for trends in psychosomatic symptoms, and for gender differences in symptoms. Results show that the effects of school stress on psychosomatic symptoms have become stronger over time, but that they can only account for a small share of the overall increase in symptoms since 1993. However, school stress has increased more among girls than among boys, and it explains about half of the growth of the gender gap in symptoms. Thus, school stress accounts for a substantial portion of the increase in symptoms for girls, but only a minor share of the increase for boys. In sum, we found weak evidence for the educational stressors hypothesis in regard to the overall trend in symptoms, but strong evidence for it in explaining the growing gender gap.

A latent class analysis of changes in adolescent substance use between 1988 and 2011 in Sweden: associations with sex and psychosomatic problems.

AIMS: To characterize changes in patterns of adolescent substance use in Sweden between 1988 and 2011, and to assess whether sex and psychosomatic problems were associated with substance use and whether these associations changed over time. DESIGN: Secondary analysis of repeated cross-sectional survey data. Survey data were collected eight times and analyzed as four cohorts (1988-91, 1995-98, 2002-05 and 2008-11). SETTING AND PARTICIPANTS: The sample included all 15-16-year-olds in Värmland County, Sweden (n = 20 057). MEASUREMENTS: Binary-coded substance use measures included life-time use of alcohol and tobacco, getting drunk and past school year use of inhalants. An eight-item scale was used to assess psychosomatic problems. FINDINGS: A three-class model fitted the data best (i.e. non/low use, mainly alcohol use and polysubstance use). The patterns of substance use were different among cohorts; most notably, adolescents in the last cohort had lower odds of being included in the alcohol and polysubstance use classes rather than the non/low use class than in the earlier cohorts (all Ps < 0.001). Males had higher odds than females of being in the polysubstance use class rather than the non/low use class among the first three cohorts (all Ps < 0.001) but not the last. Sex was not associated with inclusion in the alcohol use class rather than the non/low use class. Adolescents who reported more psychosomatic problems had higher odds of being included in the alcohol and polysubstance use classes rather than the non/low use class (all Ps < 0.001). The associations of sex and psychosomatic problems with class inclusion did not change during the study period. CONCLUSIONS: Between 1988 and 2011, patterns of substance use among adolescents in Sweden shifted away from polysubstance use and alcohol use to non-use or low use. Associations between patterns of substance use and sex and psychosomatic problems remained largely consistent across the study period.

Mental Health Problems Among Adolescents in Sweden from 1995 to 2011: The Role of Immigrant Status and the Proportions of Immigrant Adolescents in Their Surrounding Community.

We compared the mental health of native and immigrant adolescents in Sweden from 1995 to 2011 and examined whether the municipality-level proportion of immigrant adolescents moderated the association between individual-level immigrant status and mental health. The sample (14,189 adolescents aged 15-16) was obtained from a repeated cross-sectional study conducted from 1995 to 2011. Adolescent self-report data (gender, immigrant status, economic situation, and mental health) and municipality-level data (proportion of immigrant adolescents) were used in multilevel linear regression analyses. Immigrant adolescents reported more mental health problems than their native Swedish peers. The long-term trend in mental health problems did not differ between the two groups. The association between individual immigrant status and mental health did not differ according to the municipality-level rate of immigrant adolescents. These findings highlight the need for public health attention to and efforts to address immigrant adolescents' mental health problems in Sweden.

Explaining differential item functioning focusing on the crucial role of external information - an example from the measurement of adolescent mental health.

BACKGROUND: An overarching objective in research comparing different sample groups is to ensure that the reported differences in outcomes are not affected by differences between groups in the functioning of the measurement instruments, i.e. the items have to work in the same way for the different sample groups to be compared. Lack of invariance across sample groups are commonly called Differential Item Functioning (DIF). There is a sense in which the DIF of an item can be taken account of by resolving (splitting) the item into group specific items, rather than deleting the item. Resolving improves fit, retains the reliability and content provided by the item, and compensates for the DIF in estimation of person parameters on the scale of the instrument. However, it destroys invariance of the item's parameter value among the groups. Whether or not a DIF item should be resolved depends on whether the source of the DIF is relevant or irrelevant for the content of the variable. The present paper shows how external information can be used to investigate if the gender DIF found in the item "Stomach ache" in a psychosomatic symptoms scale used among adolescents may reflect abdominal pain because of a biological factor, the girls' menstrual periods. METHODS: Swedish data from the international Health Behaviour in School-aged Children study (HBSC) collected in 2005/06, 2009/10 and 2013/14 were used, comprising a total of 18,983 students in grades 5, 7 and 9. A composite measure of eight items of psychosomatic problems was analysed for DIF with respect to gender and menstrual periods using the Rasch model. RESULTS: The results support the hypothesis that the source of the gender DIF for the item "Stomach ache" is a gender specific biological factor. In that case the DIF should be resolved if the psychosomatic measure is not intended to tap information about abdominal pain caused by a gender specific biological factor. In contrast, if the measure is intended to tap such information, the DIF should not be resolved. CONCLUSIONS: The conceptualisation of the measure governs whether the item showing DIF should be resolved or not.

Towards explaining time trends in adolescents' alcohol use: a multilevel analysis of Swedish data from 1988 to 2011.

BACKGROUND: Alcohol use has decreased among Swedish adolescents in the past few decades. We examined peer and parent factors (i.e. time spent with peers, time spent with parents and parental monitoring) that could contribute to explaining this trend by investigating their main effects and interaction effects with investigation years on alcohol use. We furthermore examined whether municipality-level socioeconomic conditions could contribute to explaining the trend. METHODS: We used data from a repeated cross-sectional study that took place eight times between 1988 and 2011. The study targeted all ninth grade students (15-16 years old) in Värmland County, Sweden. Adolescents (N = 22 257) reported their monthly alcohol use, time spent with peers and parents and parental monitoring. Municipality-level socioeconomic conditions were based on parent education levels. RESULTS: Logistic multilevel regression analyses showed that peer and parent factors and municipality-level socioeconomic conditions were associated with alcohol use among adolescents. The interaction effects between peer and parent factors and investigation years were not significant. The decreased trend in time spent with peers was associated with the decreased trend in frequency of alcohol use over time. CONCLUSIONS: The findings of the current study provide an indication that the decreased trend in alcohol use that has been observed in Swedish adolescents over the past few decades may be related to changes in adolescents' social interactions with peers.

Cross-country comparisons of trends in adolescent psychosomatic symptoms - a Rasch analysis of HBSC data from four Nordic countries.

BACKGROUND: To analyse the psychometric properties of the HBSC Symptom Checklist (HBSC-SCL) on psychosomatic symptoms with a focus on the operating characteristics of the items, and on the impacts of measurement distortions on the comparisons of person measures across time and between countries. METHODS: Data were collected in 1993/94, 1997/98, 2001/02, 2005/06, 2008/09, 2013/14 in Denmark, Finland, Norway and Sweden as part of the Health Behaviour in School-aged Children (HBSC) study. Data comprised 116,531 students 11, 13 and 15 years old. Rasch analysis was conducted of the HBSC-SCL consisting of eight items with a focus on Differential Item Functioning (DIF) and item threshold ordering. The impacts of DIF and threshold disordering on trend analyses were analysed in a subsample consisting of 15 years old students. RESULTS: One item shows evidence of severe DIF and the categorisation of some items does not seem to work as intended. Analyses of changes based on proportions of psychosomatic symptoms show that bad item functioning affects some comparisons between countries across time: A four percentage point difference between 15 years old girls in Finland and Sweden concerning the rate of increase of psychosomatic symptoms from 1994 to 2014 disappears when the problems with DIF and disordered item thresholds are taken into account. Although the proportions of students with psychosomatic symptoms are clearly higher 2014 than 1994 in all four countries the shape of most trends is nonlinear. CONCLUSIONS: Some of the cross-country comparisons were distorted because of DIF and problems related to disordering of the item thresholds. The comparisons among girls between Finland and Sweden were affected by the problems pertaining to the original measure of psychosomatic symptoms, while the trend patterns among boys were not much affected. In addition to confirming increasing rates of adolescent mental health problems in the Nordic countries, the substantive analyses in the current study show that Finland is joining Sweden in having the sharpest increase among older adolescents, in particular among girls. To improve the functioning of the scale the DIF item could be removed or replaced and response categories collapsed in post hoc analyses.

Self-reported school demands and psychosomatic problems among adolescents - changes in the association between 1988 and 2011?

AIMS: The aim of the present study was to examine changes over time in the relationship between self-reported school demands and psychosomatic problems, also considering the impact of student influence and teacher support. METHODS: Data from a cross-sectional study (Young in Värmland) including eight data collections (1988-2011) among Swedish students aged 15-16 were used ( n = 20,115). Analyses with multinomial logistic regression and descriptive statistics were applied. RESULTS: Between 1988 and 2011, the proportions of students with a higher degree of psychosomatic problems increased, as did the proportion of students experiencing school demands that were too high. Finer-level analyses based on stratification of student groups did not show any associations at the aggregated level between increases of school demands and psychosomatic problems. Similarly, individual level analyses showed that the strength of the association between school demands and psychosomatic problems was not affected by year of investigation. CONCLUSIONS: Changes in school demands over time could not explain the increasing trend in psychosomatic problems among adolescents. Since the relationship between school demands and psychosomatic problems is strong across time, there is, however, a continued need for school-based interventions. More studies are required to gain further understanding of adolescent mental health from a trend perspective.

Psychological distress among Norwegian adolescents: Changes between 2001 and 2009 and associations with leisure time physical activity and screen-based sedentary behaviour.

AIMS: The aim of this work was to examine psychological distress among Norwegian adolescents in relation to changes over time and the associations with leisure time physical activity and screen-based sedentary behaviour. METHODS: This cross-sectional study was based on data retrieved from the Norwegian Youth Health Surveys in 2001 and 2009 in Hedmark County. Adolescents aged 15-16 years old completed a questionnaire regarding physical activity, sedentary behaviour, psychological distress and other health and lifestyle variables. The self-report Hopkins Symptom Checklist-10 was used to assess psychological distress. Multinomial logistic regression was used to analyse the associations between psychological distress, physical activity and sedentary behaviour. RESULTS: Self-reported psychological distress increased significantly from 2001 to 2009 (from 19.4 to 28.2%), with the proportion of girls reporting psychological distress being twice as large as the proportion of boys. The proportion of adolescents who were physically active for ⩾11 hours per week increased significantly over the same period (from 6.0 to 10.4%). Sedentary behaviour ⩾6 hours per school day increased significantly among both sexes between 2001 and 2009. Physical activity (⩾11 hours) and sedentary behaviour (⩾6 hours) were both significantly associated with psychological distress. CONCLUSIONS: The association between physical activity, sedentary behaviour and psychological distress was weak; only high amounts of physical activity and high amounts of screen-based sedentary behaviour were associated with psychological distress. Longitudinal studies are needed to provide further insights into these associations and to understand the extent to which these variables might be causally related.

Leisure-time physical activity among adolescents and subsequent use of antidepressant and hypnotic drugs: a prospective register linkage study.

In this prospective study, the association between physical activity and subsequent use of antidepressant and hypnotic drug use in adolescents aged 15-16 years was examined. This study is based on information retrieved from the Norwegian Youth Health Surveys (2000-2003) and linked to prescription data from the Norwegian Prescription Database (2004-2013). In total, the study included 10711 participants with a participation rate of 87%. Adolescents were asked how many hours per week they spent on physical activity that made them sweat and/or be out of breath outside of school. Incident psychotropic drug use (outcome measure) was defined as ≥ 1 prescription of one of the following psychotropic drugs: hypnotics and antidepressants registered in the Norwegian Prescription Database. In the crude model for the time period 2004-2007, the odds of incident hypnotic use were lower for those who were physically active 1-2 h per week (OR 0.48-0.64), compared to those who were physically inactive (< 1 h per week). However, the association become non-significant 4-year post-baseline (2008-2010 and 2011-2013). In the crude model for the time periods 2004-2007, 2008-2010 and 2011-2013, the odds of incident antidepressant use were lower for physically active adolescents (2004-2007: OR 0.46-0.71, 2008-2010: OR 0.40-0.67 and 2011-2013: OR 0.37-0.58, compared to those who were physically inactive < 1 h. However, after adjustment for confounders, the association became non-significant in all time periods except in physical activity 5-7 and 8-10 h in the period 2008-2010. Physical activity does not indicate any association with later use of antidepressants, and the significant association with incident hypnotic drug use was for short-term follow-up only and disappeared on longer term follow-up periods. Given the scarcity of longitudinal studies examining the association between physical activity and mental health as well as psychotropic drug use among young people, the current study adds to previous research.

The association between physical activity and symptoms of depression in different contexts - a cross-sectional study of Norwegian adolescents.

BACKGROUND: The purpose was to analyse the association between physical activity taking place in different contexts (sports club, gym, exercise independently and other organized physical activities) and symptoms of depression. METHODS: The study was based on self-reported cross-sectional data from the Ungdata survey, conducted in 2017 by the Norwegian Social Research (NOVA) institute in cooperation with regional centres for drug rehabilitation. The target group comprised 5531 15-16 years old adolescents (Grade 10 students) and 11,655 students in grades 8 and 9 in Norway. Based on Rasch analysis, six items on depressions symptoms were used to create a composite measure of depression. Binomial logistic regression was used to analyse the association between physical activities in different contexts and symptoms of depression. RESULTS: In the crude model, the odds for symptoms of depression were lower for those who were physically active in a sports club (OR: 0.40, 95% CI: 0.30-0.53), in a sports club and gym (OR: 0.40, 95% CI: 0.28-0.56), in a sports club and exercise or keep fit independently (OR: 0.52, 95% CI: 0.38-0.72) and in a sports club, gym and exercise or keep fit independently (OR: 0.58, 95% CI: 0.41-0.81). After adjustment for potential confounders, the association became significant only for those who were physically active in a sports club (OR: 0.57, 95% CI: 0.40-0.81) and other organized physical activities, e.g. dance, martial arts (OR: 0.52, 95% CI: 0.31-0.86). Analysis for grade 8 and 9 showed the same patterns for the associations between sports club and symptoms of depression (grade 8: crude model, OR: 0.47, adjusted model, OR: 0.63, grade 9: crude model, OR: 0.44, adjusted model, OR: 0.49). CONCLUSIONS: Physical activity in a sports club was associated with significantly lower odds for symptoms of depression, suggesting a possible role for social interaction in addition to physical activity per se. It is important, therefore, to consider in which types of contexts physical activities take place, not only focusing on physical activity frequency and volume when investigating the association between adolescents' physical activity and mental health. Additional research is needed to further explore these associations as well as measures of physical activity and mental health.