What would be an indication of teen depression and what should i do to feel better?

Signs: Depression in teenagers may look like a bad child instead of a sad child. Teens may begin smoking, drinking alcohol or using drugs. They may stop doing homework and academics may take a nose dive. Arguments with parents and siblings may increase. They may be irritable. A previously compliant teen may now become a defiant one. They may isolate from others & stop participating in activities. That >.