The global health organisation said this in a report: ‘Coming of age: Adolescent health’ to mark the World Mental Health Day commemorated on Wednesday.
Worldwide, it is estimated that one in five adolescents experience mental health challenges, though most remain under-diagnosed and untreated.
Tarun Dua, mental health expert at WHO, explained: “Half of mental health disorders arise before the age of 14.
“If these are left untreated, they extend into adult life, thus impacting educational attainment, employment, relationships or even parenting.”
According to WHO, depression is one of the leading causes of illness and disability among adolescents and suicide is the second leading cause of death among 15 to 29-year-olds.
The harmful use of alcohol and illicit drugs among adolescents is a major issue in many countries and can lead to self-destructive behaviours such as unsafe sex or dangerous driving.
Eating disorders are also of concern, the global health agency warned.
WHO noted that “evidence is growing that promoting and protecting adolescent mental health benefits not just adolescents’ health, in the short- and the long-term.
“It also promotes economies and society as a whole, with healthy young adults able to make greater contributions to the workforce, their families and communities.”
WHO recommended investing in greater integration of mental health into broader health and social care systems, under the umbrella of universal health coverage.
It also recommended investing in mental health resilience-building through parents and teachers; and psycho-social provision in schools and community spaces, especially in hardship contexts such as conflict and natural disaster settings.
António Guterres, UN secretary-general, urged adolescents to start nurturing their mental health “at an early age”.
He said: “Poor mental health during adolescence has an impact on educational achievement and increases the risk of alcohol and substance use and violent behaviour.
“A great deal of mental health conditions are both preventable and treatable, especially if we start looking after our mental health at an early age.
“The United Nations is committed to creating a world whereby 2030 everyone, everywhere has someone to turn to, in support of their mental health, in a world free of stigma and discrimination.
“If we change our attitude to mental health – we change the world. It is time to act on mental health.”