Mental Illness and Addiction: 2 Sides of the Same Coin

What are co-occurring disorders?

A large number of patients who suffer from mental illness also suffer from tobacco, alcohol, and substance use disorders. We used to refer to patients with these comorbid conditions as suffering from ‘dual disorders.’ But, over time, it became clear that there were not just two, but rather, many conditions that clustered together in a significant number of patients. Now, we refer to these patients as suffering from ‘co-occurring disorders.’ According to the National Comorbidity Survey, approximately 50% of those with schizophrenia also have a substance use disorder, approximately 60% of those with bipolar disorder also have a substance use disorder, and approximately 33% of those with depression also have a substance abuse disorder.

The complex co-occurrence of substance use disorders and mental health problems can cause significant difficulties for these patients, including an increased risk of relapse, suicide, and aggression, leading to more frequent hospitalizations and legal problems. They also have a more difficult time sticking to a treatment plan. These co-occurring disorders can result in an increased burden on family, greater interpersonal conflicts, housing instability, and even homelessness. Furthermore, because these patients tend to engage in more high-risk behaviors, there is a higher likelihood of health problems like HIV and hepatitis.

How have we tried to treat co-occurring disorders?

There has been an evolution of treatment models to treat patients with co-occurring disorders over the years. The earliest model was one of sequential treatment. In this approach, a patient was not eligible for mental health treatment until the substance use disorder was treated first. Unfortunately, it prevented patients from receiving good care because the untreated mental health disorder would contribute to a worsening of the treated disorder, making it impossible to stabilize one disorder without stabilizing the other- This kind of treatment was termed ‘ping pong’ therapy. If a patient’s mental health issues were more than the addiction treatment facility could handle, the patients were often just discharged from care.

The next model was parallel treatment, in which the patient enrolled him/herself into treatment with mental health and addiction professionals simultaneously. Often the treatment providers would not communicate with each other and the necessary task of integration fell on the patient. Different professionals would often have conflicting treatment philosophies. All of these factors made it easier for patients to slip through the cracks. There was a growing body of evidence that demonstrated poor prognoses for patients treated with the sequential and parallel approaches.

What works: the integrated model

Over time, we’ve learned that the most effective model of care for these disorders is the integrated treatment model. Both mental health and addiction services are provided by the same team; both categories of disorders are considered ‘primary’ and are treated simultaneously. Because both disorders are prioritized and treated with utmost importance, this model has the best outcomes. As medical professionals, we are able to work together and in tandem to simultaneously address these co-occurring disorders for the best chance of a positive outcome.

Clients with co-occurring disorders are not a rarity. Every mental health and addiction program should embrace this reality and provide ‘person-centered care’ to this group of patients. As a national health care system, we still have a long way to go to make this into a reality, but we are continuing to make strides in the right direction.


Sunil Khushalani, M.D., is service chief of the inpatient Co-Occurring Disorders Program and the Adult Day Hospital on Sheppard Pratt Health System’s Towson campus. His primary focus is providing integrated treatment to adult psychiatric patients with co-occurring disorders.