Some of the most common co-occurring disorders found in chemically dependent people include mood and anxiety disorders. An even higher percentage of people with severe mental illness also have co-occurring disorders that are substance abuse related. Called severe because of the severity and length of episodes of illness, these mental health disorders include schizophrenia and schizo-affective disorder. (These latter two disorders with their symptoms of hallucinations or delusions are also sometimes called “thought disorders”).

People who have substance use disorders in addition to mental health disorders are diagnosed as having co-occurring disorders, or dual disorders. This is also sometimes called a dual diagnosis.

When referring to substance abuse, we’re referring to:

• alcohol or drug abuse
• alcohol or drug dependence

Alcohol or drug abuse is diagnosed when substance use interferes with functioning at work, at school, and in social relationships. It is also diagnosed when substance use creates or worsens a medical condition or when substance use occurs in dangerous situations.

Alcohol or drug dependence is a more severe condition than alcohol or drug abuse. In addition to facing more negative consequences, people with dependence have failed in their attempts to abstain from or control their use of substances. In some cases, physiological dependence may also exist, which is indicated by heightened tolerance (needing more of a substance to get the same effect) and withdrawal (experiencing symptoms such as tremors or nausea when substance use has stopped).

Some common mental health disorders:

Mood-related disorders

• Major depression
• Dysthymia
• Bipolar disorder

Severe Mental Illness

• Schizophrenia
• Schizoaffective disorder

Anxiety-related disorders

• Post-traumatic stress disorder
• Panic disorder
• Social anxiety
• Generalized anxiety disorder
• Obsessive-compulsive disorder

Co-occurring Disorders

Co-occurring disorders can sometimes be difficult to diagnose. Symptoms of substance abuse or addiction can mask symptoms of mental illness, and symptoms of mental illness can be confused with symptoms of addiction. People with mental health disorders sometimes do not address their substance use because they don’t believe it is relevant to their problems.

However, some typical patterns do emerge among those with co-occurring disorders:

A worsening of mental health symptoms even while receiving treatment. Those diagnosed with mental health disorders often use substances to feel better. People who are anxious may want something to make them feel calm; people who are depressed may want something to make them feel more animated; people who are fearful of others may want something to make them feel more relaxed and less inhibited; and people who are in psychological pain may want something to make them feel numb.

Using alcohol or other drugs not only fails to repair the mental health disorder but also prevents a person from developing effective coping skills, having satisfying relationships, and feeling comfortable with themselves. Alcohol also interferes with medications prescribed for mental health disorders. In short, drug and alcohol use makes mental health disorders worse. These co-occurring disorders can rapidly increase the rate of deterioration in patient’s physical health and can dramatically worsen their mental health conditions.

Alcohol or substance use problems that seem resistant to treatment. People with co-occurring disorders may stop using alcohol or other drugs, but they will find difficulties as the symptoms of their mental health disorders persist. Treatment centers and clinicians and addiction specialists may not be prepared to address both conditions. And some traditional peer recovery groups may insist on abstinence from all drugs – even medications prescribed for mental health disorders. As a result, people with co-occurring disorders find it very difficult to treat their substance-use problems without also treating their mental health disorders.

Causes

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. Co-occurring disorders present unique challenges during the treatment process.

Treatments

To provide appropriate treatment for co-occurring 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.

Conclusions

Although the nature of the relationship between psychiatric disorders and substance use disorders is complex and multifaceted, there are likely to be unifying constructs. Neuroadaptations in brain stress and reward pathways associated with chronic stress may predispose or unmask a vulnerability to psychiatric disorders, substance use disorders, or both. Dysfunction in the prefrontal cortex and frontal cortex associated with deficits in self-monitoring and behavioral control are evident in ADHD, other externalizing disorders, and substance use disorders. Emerging evidence suggests that abnormalities of glutamatergic function in schizophrenia and other psychiatric disorders may mediate vulnerability to the development of substance use disorders. Although the focus of this article has been on neurobiological connections between psychiatric and substance use disorders, it is important to note that these connections constitute just one facet of a complex issue. Further exploration of overlapping neural circuitry and mechanistic relationships will be essential in guiding treatment and prevention efforts.