Psychological symptoms and physical health and health behaviours in adolescents: a prospective 2-year study in East London.

Aims: To examine whether physical health and health-risk behaviours in young people are risk factors for psychological distress and depressive symptoms over a 2-year period.
Design/setting: A 2-year, prospective epidemiological cohort study in East London.
Participants: A total of 1615 adolescents from the Research with East London Adolescents: Community Health Survey (RELACHS)-a representative cohort of young people aged 11-12 and 13-14 years at baseline, followed-up after 2 years.
Measurements: Psychological distress and depressive symptoms identified by the self-report Strengths and Difficulties Questionnaire and the Short Moods and Feelings Questionnaire at baseline and follow-up. Data on overweight/obesity, general health, long-standing illness, physical activity, smoking, alcohol use and drug use were collected from questionnaires completed by the adolescents at baseline and follow-up.
Findings: At follow-up, 10.1% of males and 12.9% of females reported psychological distress; 20% of males and 33.7% of females reported depressive symptoms. Having tried drugs or engaged in two or more health-risk behaviours (smoking, alcohol use or drug use) at baseline predicted psychological distress and depressive symptoms at follow-up. Smoking on its own, long-standing illness, obesity/overweight and activity levels were not associated with later psychological health. Risk of poor psychological health at follow-up was associated strongly with psychological health at baseline.
Conclusions: Psychological health at baseline was the strongest predictor of psychological health at follow-up. Engaging in two or more health-risk behaviours moderately increased the risk of poor psychological health, suggesting that prevention strategies targeting co-occuring substance use may reduce burden of disease.