Teenagers 13 to 18
The most common mental illnesses in adolescents are anxiety, mood, attention, and behavior disorders. Being irritable and intolerant of others, little or no enjoyment of things that were once interesting to them. increasing social isolation. disturbed sleep patterns (for example, problems going to sleep and/or waking throughout the night) Suicide is the second leading cause of death in young people aged 15–24 years.