Updated March 07, 2014.
Written or reviewed by a board-certified physician. See About.com's Medical Review Board.
Depression cannot directly kill you the way that an illness like cancer or tuberculosis might, but it can have certain effects that could lead indirectly to a person being more likely to die.
Depression Increases the Risk for Suicide
The most obvious way that depression might lead to death is if the bad feelings of depression lead a person to decide to take his own life. Depression can make people feel helpless and without hope, causing them to reach the unfortunate conclusion that suicide is the only way to end their misery.
According to the Centers for Disease Control and Prevention, suicide was the tenth leading cause of death among all age groups in the year 2010. In addition, there were 38,364 deaths attributed to suicide in the U.S. that year.
Depression May Cause People to Self-Medicate
Some people with depression, if they have never learned other ways to cope with their bad feelings, may turn to drugs and/or alcohol to sooth their painful feelings. When they develop unhealthy dependency on these substances, however, this is called dual diagnosis. Dual diagnosis complicates the treatment of depression since both conditions must be dealt with as separate, but interconnected, issues.
The National Institute on Drug Abuse reports that one in four deaths in America can be blamed on alcohol, tobacco and illegal drug use. In addition, according to the Substance Abuse and Mental Health Services Administration, substances abuse is one of the biggest risk factors for suicide.
Depression May Complicate Other Illnesses
Depression can make co-existing illnesses harder to treat because a person who is not feeling well emotionally will have a harder time complying with his treatment regimen. In addition, people with depression appear to at greater risk for contracting certain illnesses, such a heart disease, in the first place. These factors, working together, may put people at greater risk for dying from their illness than they otherwise would be if they did not have depression.
Depression May Lead to Poor Lifestyle Choices
When a person is depressed it makes it harder for him to make good lifestyle choices. He may not sleep or eat well, he may not get much exercise or he may drink, smoke or use drugs. All of these factors can contribute to putting a person at higher risk for illness and poor health, which, in turn, makes a person more likely to die prematurely.
Sources:
"Dual Diagnosis and Recovery." Depression and Bipolar Support Alliance. Accessed: December 23, 2013.
"How Depression Affects Your Body." WebMD Medical Reference. Reviewed by: Joseph Goldberg, MD on May 22, 2012. WebMD, LLC. Accessed: November 25, 2013.
Katon, Wayne. "Treating Patients with Comorbid Medical Illness." The Carlat Psychiatry Report. 2013. Psych Central Professional. Accessed: December 23, 2013.
"Medical Consequences of Drug Abuse." National Institute on Drug Abuse. December 2012. National Institutes of Health. Accessed: December 23, 2013.
"Suicide: Facts at a Glance." National Center for Injury Control and Prevention. 2012. Centers for Disease Control and Prevention. Accessed: December 23, 2013.
