When teenagers are struggling with emotional problems, they often turn to alcohol or drug use to help them manage painful or difficult feelings. In this they are not different from adults. But because adolescent brains are still developing, the results of teenage "self-medication" can be more immediately problematic.

In the short term, substance use can help alleviate unwanted mental health symptoms like hopelessness, anxiety, irritability and negative thoughts. But in the longer term it exacerbates them, and often ends in abuse or dependence. Substance use escalates from experimentation to a serious disorder much faster in adolescents than it does in adults, and that progression is more likely to happen in kids with mental health disorders than in other kids.

Substance use also interferes with treatment for mental health disorders and worsens the long-term prognosis for a teenager struggling with one.