Co-Occurring Disorders

Formerly known as dual diagnosis or dual disorder, co-occurring disorders describes the presence of both a mental health and a substance-use disorder. For example, a person may be abusing a narcotic and also have bipolar disorder.


The term co-occurring disorder replaces the terms dual disorder and dual diagnosis when referring to an individual who has a co-existing mental illness and a substance-use disorder. While commonly used to refer to the combination of substance-use and mental disorders, the term also refers to other combinations of disorders (such as mental disorders and intellectual disability).

Clients with co-occurring disorders (COD) typically have one or more disorders relating to the use of alcohol and/or other drugs as well as one or more mental disorders. A client can be described as having co-occurring disorders when at least one disorder of each type can be established independent of the other and is not simply a cluster of symptoms resulting from another disorder.

Common examples of co-occurring disorders include the combinations of major depression with cocaine addiction, alcohol addiction with panic disorder, alcoholism and poly-drug addiction with schizophrenia, and borderline personality disorder with episodic poly-drug abuse. Thus, there is no single combination of co-occurring disorders; in fact, there is great variability among them.

The combination of a substance-use disorder and a psychiatric disorder varies along important dimensions, such as severity, chronicity, disability, and degree of impairment in functioning. For example, the two disorders may each be severe or mild, or one may be more severe than the other. Additionally, the severity of both disorders may change over time. Levels of disability and impairment in functioning may also vary.

People with co-occurring disorders often experience more severe and chronic medical, social, and emotional problems than people experiencing a mental health condition or substance-use disorder alone. Because they have two disorders, they are vulnerable to both relapse and a worsening of the psychiatric disorder. Further, addiction relapse often leads to psychiatric distress, and worsening of psychiatric problems often leads to addiction relapse. Thus, relapse prevention must be specifically designed for the unique needs of people with co-occurring disorders. Compared to patients who have a single disorder, patients with co-existing conditions often require longer treatment, have more crises, and progress more gradually in treatment.

Approximately 7.9 million adults in the United States had co-occurring disorders in 2014.


The symptoms of co-occurring disorders include those associated with the particular substance-abuse and mental health conditions a person has. Co-occurring disorders can be difficult to diagnose because the symptoms of substance abuse or dependence can mask the symptoms of a mental illness, and vice versa.

Substance abuse is a maladaptive pattern of substance use that occurs despite the individual's experiencing significant substance-related problems. Individuals who abuse substances may experience such harmful consequences of substance use as repeated failure to fulfill roles for which they are responsible, legal difficulties, or social and interpersonal problems. It is important to note that the chronic use of an illicit drug still constitutes a significant issue for treatment even when it does not meet the criteria for substance abuse.

For individuals with more severe or disabling mental disorders, as well as for those with developmental disabilities and traumatic brain injuries, substance use at lower levels might be more harmful (and therefore defined as abuse) than for individuals without such disorders.

People with co-occurring disorders are at high risk for many additional problems such as symptomatic relapses, hospitalizations, financial problems, social isolation, family problems, homelessness, suicide, violence, sexual and physical victimization, incarceration, serious medical illnesses such as HIV and hepatitis B and C, and early death. Any one of these problems complicates the treatment of co-occurring disorders.


Mental health and substance-abuse disorders often occur as a result of biological and environmental factors. Mental disorders and addiction are each a dynamic process, with varying degrees of severity, rate of progression, and symptom manifestation. Both types of disorders are greatly influenced by several factors, including genetic susceptibility, environment, and pharmacologic influences. Certain people have a high risk for these disorders (genetic risk); some situations can evoke or help to sustain these disorders (environmental risk); and some drugs are more likely than others to cause psychiatric or substance use disorder problems (pharmacologic risk).

People with mental health disorders are more likely than people without mental health disorders to experience an alcohol or substance-use disorder. Mental illness can lead people to use alcohol or drugs to make themselves feel better temporarily. In other cases, a substance-abuse disorder triggers or in some other way leads to severe emotional and mental distress.


To provide appropriate treatment for co-occuring disorders, the Substance Abuse and Mental Health Services Administration (SAMHSA) of the U.S. Department of Health and Human Services recommends an integrated treatment approach. Integrated treatment is a means of coordinating substance-abuse and mental health interventions, rather than treating each disorder separately and without consideration for the other.

Integrated treatment occurs when a person receives combined treatment for mental illness and substance use from the same clinician or treatment team. It helps people develop hope, knowledge, skills, and the support they need to manage their problems and to pursue meaningful life goals. Integrated treatment may include the following:

  • Help patients think about the role that alcohol and other drugs play in their life. People feel more free to discuss these issues when the discussion is confidential, nonjudgmental, and not tied to legal consequences.
  • Offer patients a chance to learn more about alcohol and drugs—how they interact with mental illnesses and with other medications—and to discuss their own use of alcohol and drugs.
  • Help patients become involved with supportive employment and other services that may help the process of recovery.
  • Help patients identify and develop recovery goals. If a person decides that the use of alcohol or drugs may be a problem, a counselor trained in integrated treatment can help that person identify and develop personalized recovery goals. This process includes learning about steps toward recovery from both illnesses.
  • Provide counseling specifically designed for people with co-occurring disorders. This can be done individually, with a group of peers, with family members, or with a combination of these.

Successful strategies with important implications for clients with COD include interventions based on addiction work in contingency management, cognitive-behavioral therapy (CBT), relapse prevention, and motivational interviewing.

All substance-abuse treatment programs should have in place appropriate procedures for screening, assessing, and referring clients with CODs. It is the responsibility of each provider to identify clients with both mental and substance-use disorders and to assure them that they have access to the care needed for each disorder.

A comprehensive assessment serves as the basis for an individualized treatment plan. Appropriate treatment plans and treatment interventions can be quite complex, depending on what might be discovered in each domain. This leads to another fundamental principle: There is no single, correct intervention or program for individuals with COD's. Rather, the appropriate treatment plan must be matched to individual needs according to these multiple considerations.

An onsite addiction treatment psychiatrist can improve treatment retention and decrease substance use among patients. The onsite psychiatrist brings diagnostic, medication, and psychiatric counseling services directly to the location where clients are based for the major part of their treatment. This approach often is the most effective way to overcome barriers presented by offsite referral, including distance and travel limitations, the inconvenience of enrolling in another agency and of the separation of clinical services (more "red tape"), client fears of being seen as mentally ill (if referred to a mental health agency), cost, and the difficulty of becoming comfortable with different staff.


Many clients with COD require medication to control their psychiatric symptoms. Pharmacological advances over the past decade have produced antipsychotic, antidepressant, anticonvulsant, and other medications with greater effectiveness and fewer side effects. With the support available from better medication regimens, many people who once would have been too unstable for substance abuse treatment, or institutionalized with a poor prognosis, have been able to lead more functional lives.

Psychoeducational Classes

Psychoeducational classes on mental and substance-use disorders are important elements in basic COD programs. These classes typically focus on the signs and symptoms of mental disorders, medication, and the effects of mental disorders on substance-abuse problems. Psychoeducational classes of this kind increase client awareness of their specific problems and do so in a safe and positive context.

Relapse-prevention education presents strategies designed to help clients become aware of cues or "triggers" that make them more likely to abuse substances and help them develop alternative coping responses to those cues. Some providers suggest the use of "mood logs" that clients can use to increase their consciousness of the situational factors that underlie the urge to use drugs or drink.

Onsite Double Trouble Groups

Onsite groups such as "Double Trouble" provide a forum for discussion of the interrelated problems of mental disorders and substance abuse, helping participants to identify triggers for relapse. Clients describe their psychiatric symptoms (such as hearing voices) and their urges to use drugs. They are encouraged to discuss, rather than to act on, these impulses. Double Trouble groups also can be used to monitor medication adherence, psychiatric symptoms, substance use, and adherence to scheduled activities. Double Trouble provides a constant framework for assessment, analysis, and planning. Through participation, the individual with COD develops perspective on the interrelated nature of mental disorders and substance abuse and becomes better able to view his or her behavior within this framework.

Dual Recovery Mutual Self-Help Groups (Offsite)

These offsite self-help groups exist in many communities. Substance-abuse treatment programs can refer clients to dual recovery mutual self-help groups, which are tailored to the special needs of a variety of people with COD. These groups provide a safe forum for discussion about medication, mental health, and substance-abuse issues in an understanding, supportive environment wherein coping skills can be shared.

The dual recovery mutual self-help movement is emerging from two cultures: the 12-step fellowship recovery movement and, more recently, the culture of the mental health consumer movement. In keeping with traditional 12-step principles and traditions, dual recovery 12-Step fellowships do not provide specific clinical or counseling interventions, classes on psychiatric symptoms, or any services similar to case management. Dual recovery fellowships maintain the primary purpose of members helping one another achieve and maintain dual recovery, prevent relapse, and carry the message of recovery to others who experience co-occurring disorders. Dual recovery 12-Step members who take turns chairing their meetings are members of their fellowship as a whole.

Substance-abuse groups include the 12-step programs of Alcoholics Anonymous (AA), Narcotics Anonymous (NA), and Cocaine Anonymous (CA). These groups can provide needed support and encouragement for patients in treatment. While self-help programs are not considered treatment per se, they are integral adjuncts to professional treatment services.

Outpatient Substance Abuse Treatment Programs for Clients with COD

Treatment for substance abuse occurs most frequently in outpatient settings. Some offer several hours of weekly treatment, which can include mental health and other support services as well as individual and group counseling for substance abuse. Others provide minimal services, such as one or two brief sessions to give clients information and refer them elsewhere. Some agencies offer intensive outpatient programs that provide services several hours per day and several days per week. Typically, treatment includes individual and group counseling, with referrals to appropriate community services.

Individuals with COD often need a range of services besides substance-abuse treatment and mental health services. Generally, important needs include housing and case management services to establish access to community health and social services. These can be essential to the successful recovery of the person with COD.

It is imperative that discharge planning for the client with COD ensures continuity of psychiatric assessment and medication management, without which client stability and recovery will be severely compromised. Relapse-prevention interventions after outpatient treatment need to be modified so that clients can recognize symptoms of psychiatric or substance-abuse relapse on their own and can call on a learned repertoire of symptom management techniques (such as self-monitoring, reporting to a "buddy," and group monitoring). This also includes the ability to access assessment services rapidly, since the return of psychiatric symptoms can often trigger substance-abuse relapse.

The Medical System

Although not substance-abuse treatment settings per se, acute care and other medical settings are included here because important substance-abuse and mental health interventions do occur in medical units. Acute care refers to short-term care provided by intensive-care units, brief hospital stays, and emergency rooms (ERs). Providers in acute-care settings are not usually concerned with treating substance-use disorders beyond detoxification, stabilization, and/or referral.

In other medical settings, such as primary care offices, providers generally lack the resources to provide any kind of extensive substance-abuse treatment, but may be able to provide brief interventions and treatment referrals.

Primary health care providers (physicians and nurses) have historically been the largest single point of contact for patients seeking help with co-occurring disorders. Physicians and nurses are uniquely qualified to manage life-threatening crises and to treat medical problems related and unrelated to psychiatric and substance-use disorders. Because they are in contact with such large numbers of patients, they have an exceptional opportunity to screen and identify patients with co-occurring disorders. At that point, the person with COD can be referred for appropriate services in the proper setting.

Find a Co-Occurring Disorder Treatment Center here.


  • American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition
  • American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
  • Office for Treatment Improvement, Alcohol, Drug Abuse, and Mental Health Administration
  • Substance Abuse and Mental Health Services Administration. 2014 National Survey on Drug Use and Health (NSDUH).
  • Center for Substance Abuse Treatment

Last reviewed 02/07/2019