AbstractBackgroundPoor adolescent mental health is a growing concern over recent decades with evidence of increasing internalising mental health problems corresponding with decrease in anti-social, smoking and alcohol behaviours. However, understanding whether and how the associations between mental health and health-related behaviours such as substance use, anti-social behaviour and obesity have changed over time is less well-understood.ObjectivesWe investigate whether the associations between different health-related outcomes in adolescence are stable or changing over time in two recent cohorts of adolescents born ten years apart.MethodData from two UK birth cohort studies, the Avon Longitudinal Study of Parents and Children (ALSPAC, born 1991-92, N=5627, 50.7% female) and Millennium Cohort Study (MCS, born 2000-1, N=11318, 50.6% female) at age 14 sweeps are used. The health outcomes of focus are depressive symptom score, substance use (alcohol, smoking, cannabis and other drugs), antisocial behaviours (assault, graffiti, vandalism, shoplifting and rowdy behaviour), weight (BMI), weight perception (perceive self as overweight) and sexual activity (had sexual intercourse).ResultsOur results suggest although directions of associations between mental-health and health-related behaviours (eg smoking) are similar over time, their strength across the distribution has changed. While smoking and alcohol use behaviours are decreasing in adolescents, those that endorse these behaviours in 2015 are more likely to have co-occurring mental-health and other problems than those born in 2005. Similarly, higher body mass index is more strongly associated with depressive symptoms in 2015.ConclusionsOur findings suggest that associations between these factors has changed over time, which has implications for public health and our understanding of the mechanisms underlying their observed associations in the population.
Modeling substance use in emerging adult gay, bisexual, and other YMSM across time: The P18 cohort study