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Co-Occurring Disorders


Co-Occurring disorders are present when there are two or more disorders at the same moment and these disorders were also called dual diagnosis or dual disorder. For instance, an individual can go through substance dependency while having bipolar disorder, too.

Just like the area of treatment for drug use and psychological disorders has developed to become more exact, the terminology that is employed to describe people who suffer both from psychological disorders and drug use has also become more precise.


The two terms dual diagnosis and dual disorder are replaced by the term, co-occurring disorders. These latter terms, though used commonly to point to the mixture of substance abuse and mental disorders, are confusing in that they also point to other mixtures of disorders (like mental retardation and mental disorders).

Additionally, the terminology may denote of the occurrence of just two disorders simultaneously when as a matter of fact there could be others, too. People who have co-occurring disorders also referred to as COD, often have at least one mental disorder and at least one disorder springing from alcohol or substance abuse as well. When a minimum of one disorder of both types can be confirmed which isn't dependent on the other, we can talk about diagnosing co-occurring disorders and it isn't just a bunch of symptoms that are caused by just one disorder.

Even though the term co-occurring disorder is the most up to date term that is used by professionals, the term dual disorders will be used interchangeably for the objectives of this article.


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The acronym MICA (short for Mentally Ill Chemical Abusers) is sometimes used to label people with a co-occurring disorder and a noticeably serious and chronic mental disorder like bipolar disorder or schizophrenia. A preferred definition is mentally ill chemically affected people since their condition is better described by the word affected and is not derogatory. Other acronyms that are used to refer to people with COD are CAMI, Chemical Abuse and Mental Illness; MIC'D, Mentally Ill Chemically Dependent; MISA, Mentally Ill Substance Abusers; MISU, Mentally Ill Substance Using; Sami, Substance Abuse and Mental Illness and ICO PSD, Individuals with co-occurring psychiatric and substance disorders.

Combinations of alcohol addiction with panic disorder, major depression with cocaine addiction, borderline personality disorder with episodic polydrug abuse, and alcoholism and polydrug addiction with schizophrenia are some of the most usual cases of co-occurring disorders. Some patients have more than two disorders although the article focuses more on dual disorders. The concept that applies to dual disorders normally applies also to multiple disorders.

The mixture of psychiatric disorders and COD problems differ along important dimensions like chronicity, disability, severity, and degree of impairment in functioning. For instance, each of the two disorders may be serious or mild, or one may be more serious than the other. However, with time, the extremity of both disorders might change. Degrees of impairment in functioning and disability might also differ.

That means that, in fact, there are many differentiations among co-occurring disorders, not just one combination. This is not to rule out the fact that one can come across patients who have the same combination of disorders in the course of treatment.


More than half of all adults with serious mental illness are further caused by substance use disorders (abuse or addiction related to alcohol or other drugs).


Patients that have co-occurring disorders commonly feel stronger and chronic medical, emotional and social issues compared to those that only have a mental disorder or COD without the other. They are susceptible, since they have two disorders, to both further impairment of mental disorder and COD relapse. What's more, an addiction relapse frequently results in psychiatric decompensation and when mental problems worsen it frequently results in addiction relapse. Thus, for patients with dual disorders relapse prevention must be specially designed. Users with dual disorders commonly need longer rehab, have a greater number of crises and advance more slowly in treatment compared to patients that only have a single disorder.

Mental disorders that are most common amongst dually diagnosed people are personality disorders, mood disorders, psychotic disorders and mood disorders.