Comorbidity refers to the condition where an individual is diagnosed with more than one type of medical condition or psychological disorder.
When people are consistently diagnosed with two or even more different psychological disorders at the same time, clinicians refer to these disorders as being comorbid with each other.
In a sense then, any situation where there are two or more comorbid disorders in an individual could be considered as a situation of co-occurring disorders. However, one of the most common pairings of different disorders is a specific mental health disorder (a psychological or psychiatric disorder) and a comorbid diagnosis of a substance use disorder (substance abuse or addiction). When clinicians encounter this, they commonly use the terms co-occurring disorders or dual diagnosis to specify this type of situation.
How Common Are Co-occurring Disorders?
It is common for someone to be diagnosed with more than one type of mental health disorder. Some of the statistics regarding co-occurring diagnoses from the National Institute of Mental Health and the Substance Abuse and Mental Health Services Administration indicate the following:
- Approximately a third of everyone diagnosed with a mental illness also have a diagnosable substance use disorder.
- About half of all people living with a severe mental illness, such as bipolar disorder, schizophrenia, post-traumatic stress disorder, etc., also have a substance use disorder.
- Individuals who come from lower socioeconomic backgrounds are more likely to develop co-occurring disorders.
- Approximately a third of individuals with alcohol use disorders, and more than one half of all other individuals with substance use disorders, likely have a co-occurring mental illness.
- People with co-occurring diagnoses are more likely to have serious medical conditions as well.
- Veterans have disproportionately high rates of co-occurring disorders compared to the general population.
- Men are significantly more likely to be diagnosed with a co-occurring disorder than women.
- Individuals with co-occurring diagnoses are disproportionately represented in local, state, and federal prison populations, such that a high proportion of these individuals wind up incarcerated.
Common Candidates for Co-occurring Disorders
The American Society of Addiction Medicine (ASAM) has discussed professional policies regarding dealing with co-occurring disorders. ASAM also lists the different mental health disorders that are most commonly associated with some type of substance use disorder. These include:
- Anxiety disorders, such as phobias, panic disorder, agoraphobia, and social anxiety disorder
- Major depressive disorder and other types of depressive disorders
- Bipolar disorders
- Attention deficit disorder
- Stress and trauma-related disorders, such as posttraumatic stress disorder
- Eating disorders, such as bulimia nervosa or anorexia nervosa
- Certain personality disorders, such as borderline personality disorder and antisocial personality disorder
- Schizophrenia and other psychotic disorders
Any type of substance use disorder can be comorbid with a form of mental illness; however, certain combinations are more common. Some combinations that are relatively common include:
- Major depressive disorder and alcohol use disorder
- Anxiety disorders and alcohol use disorders
- Antisocial personality disorder and alcohol use disorders or cocaine use disorders
- Schizophrenia and tobacco use disorder or cannabis use disorder
The relationship between the mental illness and co-occurring substance use disorder is not always easy to assess. It is essentially impossible at this time to determine if one particular disorder causes or results in the development of another disorder. For example, individuals who have schizophrenia are notoriously apt to have serious tobacco use disorders or smoking issues. Part of the reason for this is believed to be that nicotine may actually alter some of the effects associated with having schizophrenia. On the other hand, individuals who have early cannabis use disorders are more likely to develop psychosis and be diagnosed with schizophrenia. Thus, the relationship between the substance use disorder and the mental illness is not always well-defined.
There is no real way to generally describe cause-and-effect in an overall sense. The development of a co-occurring disorder most likely represents an overall liability to develop mental illnesses based on one’s personal experiences, genetic factors, and other interacting factors.
Treatment Options for Co-occurring Disorders
Individuals diagnosed with co-occurring disorders present specific challenges in terms of treatment. First, individuals with co-occurring disorders also have other complicating issues that affect treatment. These include:
- Higher rates of divorce or other relationship issues
- Higher rates of violence, aggression, and self-harm, such suicide
- More medical complications, including diabetes, sexually transmitted diseases, HIV, hepatitis, and so forth
- More issues with homelessness, unemployment, or low socioeconomic status
- More issues with relapse
People with co-occurring diagnoses or any types of comorbid mental illnesses should preferentially be involved in treatment programs that address all co-occurring disorders at the same time. Research has shown indicated that trying to focus on one disorder while ignoring or holding the others constant results in very poor treatment outcomes. Only by treating the entire person and all issues can the chances of successful treatment outcomes be optimized.
This has led to the notion of using integrated treatment as the first line approach in treating someone who has a dual diagnosis. The emphasis of integrated treatment is to use a multidisciplinary approach, treat all issues concurrently, and get the individual to the most self-sufficient level possible. While integrated treatment programs follow standardized treatment outlines or blueprints for the specific mental disorders and substance use disorder in question, they also ensure a tailored approach and adjust for the changing needs of the individual.
With integrated care, the treatment is broken down in the specific stages in order to achieve the overall goals of the program. This is generally conceptualized as four related stages of overall treatment:
- Developing a strong therapeutic alliance between the treatment team and the client: The therapeutic alliance describes the level of trust in the bond that the therapist or treatment team has with the client. This relationship is an important predictor of treatment success.
- Working with the client to develop the motivation and drive to become an active agent in treatment and overall recovery: Clients cannot be passive in treatment. They must take an active role in the recovery process.
- Teaching and practicing the needed skills for managing the client’s situation: This includes helping the client to develop a support system that fosters treatment and recovery.
- Developing strategies for long-term success: This involves plans that allow the client to continue to grow, maintain improvements, and avoid relapse in the future.
Integrated treatment is delivered by a multidisciplinary team that includes physicians, therapists, social workers, case managers, and other healthcare professionals and volunteers suitable for the specific case.
In addition, treatment should incorporate the following services:
- Comprehensive care to address the specific needs of the client, such as the opportunity to be involved in residential or inpatient treatment, outpatient treatment, vocational services, occupational therapy, physical therapy, and so forth
- Psychoeducation programs to make sure that the individual understands the parameters of their formal diagnoses and the implications associated with them
- Outreach programs that provide intensive case management, periodic meetings, and unlimited time services so that assistance is always available
- Substance abuse treatment and counseling as well as support services from peer support groups, such as 12-Step groups
- The delivery of health promotion services and lifestyle change services to ensure continued improvement
The overall goal is to provide a comprehensive treatment approach that addresses all the needs of the individual. This care allows the person the best opportunity for recovery and to reach the highest possible level of autonomy.
Part of the approach in an integrated treatment program includes medically assisted treatment. The medications used in these integrated treatment programs are determined on a case-by-case basis. They may include:
- Medications to assist in negotiating the withdrawal process from drugs that produce physical dependence, such as benzodiazepines for alcohol recovery or opioid replacement therapy for recovery from opioid abuse
- Medications to decrease cravings for specific types of drugs
- Medications for the treatment of specific psychiatric disorders, such as antidepressant medications, antipsychotic medications, and so forth
- Medications to assist in the treatment of any comorbid medical conditions
All medications should be administered under the strict supervision of a physician, and dosage levels should be regularly assessed.
When looking for treatment options for an individual who has a substance use disorder that is comorbid with some other psychological condition, there are certain features a treatment program should offer.
- There should be a multidisciplinary team that can address issues from several different perspectives.
- There should at least be access to a psychiatrist to assist in medication management if needed.
- The treatment center should offer multiple types of services, including individual therapy, group therapy, case management services, vocational services, and other services as needed.
- The center should at least have access to an inpatient treatment program where clients who need comprehensive residential treatment can be placed.
- Treatment centers should provide treatment services via the use of trained, licensed mental health treatment professionals.
- The treatment center’s program should include a plan for long-term aftercare.
While the presence of co-occurring disorders can complicate the treatment process, integrated care ensures that all issues can be fully addressed, making recovery from all conditions within reach.