Co-occurring disorder refers to the coexistence of a substance use disorder—alcohol or other drug abuse or addiction—and a mental health disorder. Mental health disorders that may commonly occur with addiction include mood disorder, such as depression or bipolar disorder, and anxiety disorder, such as generalized anxiety disorder, social anxiety, panic disorder, post-traumatic stress disorder, or obsessive-compulsive disorder.
Addiction and mental illness are identified as separate and distinct issues that can—and often do—occur together. When people are diagnosed as having a co-occurring disorder, it means that they have been diagnosed with two or more disorders at the same time during the past year.
Having a co-occurring disorder can present with problems such as:
Often times there is a genetic risk factor for both substance use and certain mental health disorders, but genes alone usually don't explain all causes of co-occurring disorders. Other factors include family, environment, and life stress, including traumatic life events, poverty, and loss. Stressful experiences can also trigger genetic factors that contribute to co-occurring disorders. It is possible that people with mental health disorders may be more biologically sensitive to the effects of mood altering substances. They may use alcohol or other drugs to cope with mental health symptoms or to counter social anxiety. People who have a mental health disorder are at much higher risk of also having a substance use disorder and, conversely, people who have a substance use disorder are at much greater risk of developing a mental health disorder.
It is important to recognize that both the addiction and the mental health disorder need to be treated. Treating only one of the disorders will result in inadequate treatment and a potential worsening of the other condition. The most common treatment for co-occurring disorders involves an integrated treatment model that can stabilize both the symptoms of the co-occurring disorder and provide the foundation for lasting recovery.
Integrated treatment involves a combination of the following:
As reported in Hazelden's Research Update, Addiction and Mental Illness, the prevalence of substance use disorders in the general population is about 16 percent and nearly doubles to 29 percent for people with mental health disorders. Additionally, the publication provides the following facts and figures on the prevalence of co-occurring disorders.
Depression is often found at high levels among alcoholics and addicts seeking substance dependency treatment. As many as 80 percent of alcoholics experience depressive symptoms at some time in their lives, and 30 percent meet diagnostic criteria for major depression.
There is a strong correlation between substance use disorders and PTSD, with as many as one-third of patients meeting criteria for PTSD when they enter treatment for their alcohol/drug problems.
Rates of other anxiety disorders anxiety disorders, such as agoraphobia, panic disorder, social phobias, and general anxiety disorder, are high in treatment populations, ranging from 10 to 60 percent.
Most studies find that between 15 and 32 percent of women with alcohol/drug disorders meet diagnostic criteria for an eating disorder, like anorexia nervosa or bulimia nervosa, at some time in their lives.
While answers about co-occurrence aren't conclusive, there are many theories. The Dartmouth Psychiatric Research Center puts forth several theories, including the following:
Psychiatry is a complex field with regard to diagnostic assessment. Blood tests and lab procedures don't provide conclusive diagnoses for psychiatric illness. Co-occurring disorders can be especially problematic to diagnose because the presence of one disorder can interfere with diagnosis of the other. For example, a person with alcohol or other drug dependence is likely to manifest problems with depression or anxiety. Likewise, a person seeking medical care for depression or anxiety may downplay or deny his or her alcohol use. Conducting a comprehensive evaluation is of paramount importance because effective treatment of co-occurring disorders is diagnosis driven.
An integrated treatment approach is key, with a focus on stabilizing symptoms of the co-occurring mental health disorder while providing the patient with a foundation for recovery from addiction.