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Comorbidity

Brief Description

When two disorders or illnesses occur in the same person, simultaneously or one after another, they are called comorbid. Comorbidity also implies interactions between the illnesses that affect the course and prognosis of both. In particular, many people addicted to drugs are also diagnosed with other mental disorders and all illnesses must be treated. Although substance abuse disorders often occur concurrently with other mental illnesses, this does not me that one causes the other, even when one comes first.

Related Publications

Publication Cover

Comorbidity: Addiction and Other Mental Illnesses (Research Reports)

Published December 2008. Revised September 2010.
Introduces a report that focuses on the topic of comorbid drug use disorders and other mental illnesses, a research priority for NIDA.

A Functional Variation in the COMT Gene Modulates the Effect of Adolescent Cannabis Use on the Risk of Adult Psychosis graph

Comorbid Drug Abuse and Mental Illness (Topics in Brief)

Revised October 2007.
Provides a research update on comorbid drug abuse and mental illness, exploring why they commonly occur, how common they are, and how they can be diagnosed and treated.

Comorbidity: Addiction and Other Mental Disorders (DrugFacts)

Published March 2011.
Offers basic facts about comorbidity between drug use disorders and other mental illnesses, including why these disorders can co-occur, how common they are, and how they are diagnosed and treated. En Español

Related Resources

Other Resources

Past information on many drugs of abuse is available on our Archives site.

This page was last updated December 2012

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