Interaction of substance use with physical activity and its effect on depressive symptoms among adolescents

Mental disorders account for a large proportion of the disease burden in young people in all societies. Most mental disorders begin during youth (12-24 years of age), although they are often first detected later in life. Poor mental health is strongly related to other health and development concerns in young people, notably lower educational achievements, substance abuse, violence, and poor reproductive and sexual health. The effectiveness of some interventions for some mental disorders in this age-group have been established, although more research is urgently needed to improve the range of affordable and feasible interventions, since most mental-health needs in young people are unmet, even in high-income countries. Key challenges to addressing mental-health needs include the shortage of mental-health professionals, the fairly low capacity and motivation of non-specialist health workers to provide quality mental-health services to young people, and the stigma associated with mental disorder. We propose a population-based, youth focused model, explicitly integrating mental health with other youth health and welfare expertise. Addressing young people's mental-health needs is crucial if they are to fulfil their potential and contribute fully to the development of their communities.

Women are about twice as likely as are men to develop depression during their lifetime. This Series paper summarises evidence regarding the epidemiology on gender differences in prevalence, incidence, and course of depression, and factors possibly explaining the gender gap. Gender-related subtypes of depression are suggested to exist, of which the developmental subtype has the strongest potential to contribute to the gender gap. Limited evidence exists for risk factors to be specifically linked to depression. Future research could profit from a transdiagnostic perspective, permitting the differentiation of specific susceptibilities from those predicting general psychopathologies within and across the internalising and externalising spectra. An integration of the Research Domain Criteria framework will allow examination of gender differences in core psychological functions, within the context of developmental transitions and environmental settings. Monitoring of changing socioeconomic and cultural trends in factors contributing to the gender gap will be important, as well as the influence of these trends on changes in symptom expression across psychopathologies in men and women.