Overconsumption of alcohol and certain illegal drugs can contribute to depression and make it worse, as can withdrawal from alcohol, cocaine, or amphetamines.

Drugs can cause other mental changes as well. For example, amphetamines, cocaine, and phencyclidine (PCP) can all induce mania in people with bipolar disorder.

Brain Trauma

Neurological disorders or injury to the brain from trauma or tumors also can cause behavioral changes, anxiety, and/or mood disorders.

Publication Review By: Karen L. Swartz, M.D.

Published: 01 Mar 2011

Last Modified: 11 Sep 2013