Teen depression is a serious mental health problem that causes a persistent feeling of sadness and loss of interest in activities. It affects how your teenager thinks, feels and behaves, and it can cause emotional, functional and physical problems. These emotions negatively impact people’s lives, causing social, educational, personal and family difficulties. The reasons behind a teen's suicide or attempted suicide can be complex. Although suicide is relatively rare among children, the rate of suicides and suicide attempts increases greatly during adolescence. Suicide is the third-leading cause of death for 15- to 24-year-olds.