Our first evidence brief on adolescent mental health showed that emotional disorders — such as anxiety and depressive disorders — are the most common mental disorder among adolescents in England aged 11–16 years (experienced by 9% of young people in this age group), followed by behavioural disorders (6.2%).

Understanding long-term associations between adolescent emotional and behavioural problems during adolescence and adult outcomes is important. It provides crucial information about the impact of emotional and behavioural problems at an individual level — in terms of impairments to family life, professional life and overall quality of life — and at a societal level, in terms of the economic costs in health, education and welfare.

Summary

• Adolescents who experience persistent emotional problems, such as anxiety and depression, are at greater risk of a range of negative outcomes:
   
  • Persistent depression during adolescence is associated with a significant increased risk of depression during adulthood. This finding is not limited to those with clinical diagnoses: those with subclinical symptoms are also at risk.
  • Young people with persistent emotional problems are at an increased risk of poorer employment and educational outcomes, including school drop-out and NEET (not in education, employment or training) status.
  • Some evidence from individual studies suggests there is an association between adolescent mental health disorders and poorer general health in adulthood, social withdrawal, increased risk of intimate partner victimisation, and unplanned pregnancy.
     
• Adolescents who exhibit behavioural problems, such as conduct problems, are also at increased risk of poor adult outcomes, including:
   
  • poor mental health, such as depression and anxiety, education outcomes — school drop-out, NEET, and at work without basic education level — and a range of physical and social outcomes, including poor physical health, substance abuse, early parenthood, and drug-related and violent crime, including violence against women and children.
  • Importantly, behaviour problems do not seem to occur in isolation and often coexist with mental health problems, including depression and anxiety, and neurodevelopmental problems, including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).
     
• Being a perpetrator and/or victim of bullying is strongly associated with a range of mental health problems in young adulthood, including increased risk of anxiety disorders, depression and suicidal behaviour.
   
• These findings illustrate that issues during adolescence cast a long shadow over individuals’ life chances. The findings highlight the need to invest not just in the treatment of disorders but also in prevention and early intervention support, and the promotion of positive mental health and prosocial behaviour, to reduce vulnerabilities and enhance protective factors. Priorities include:
   
  • targeted support for young people with persistent emotional and behavioural problems
  • addressing the needs of young people with subclinical symptoms
  • further investigation of the coexistence of mental health, behavioural and neurodevelopmental problems (such as ASD and ADHD) during adolescence, and their combined impact on adult outcomes
  • addressing the significant gap in the evidence concerning the long-term impact of emotional and behavioural problems for ethnic minorities and vulnerable adolescent groups, such as young people with special educational needs and disabilities, and lesbian, gay, bisexual and transgender (LGBT) young people.
     
• Evidence-based mental health and behavioural interventions which are tailored to the needs of young people could have important consequences at both an individual and societal level. Research examining the efficacy of these interventions in improving long-term outcomes is required.