Examining Co-occurring Mental and Substance Use Disorders – A 3-Part Series

Published On: February 22nd, 2018Categories: Spectrum Corrections, Treatment & Recovery

Part 1: The Challenge of Mental Illness in Substance Abuse Treatment


This is the first of three blogs to examine co-occurring mental and substance use disorders. In this first blog, we review the prevalence of mental disorders among persons in addiction treatment, myths related to mental illness, key problems and challenges, and how to accurately identify persons with mental disorders. A second blog will explore effective treatment strategies for this population, and a third blog will focus on the importance of continuing care and transition services for persons who have co-occurring disorders.

The opioid epidemic sweeping the U.S. has created many casualties in all parts of our society. Due to the catastrophic nature of the epidemic, there is a growing awareness of the important challenges facing our nation in working with persons who have substance use disorders. We know that individuals in recovery from addiction often experience multiple relapses and have many other life problems that need to be addressed, which may have contributed to their involvement with drugs. One of the major issues in recovery is dealing with co-occurring mental disorders such as depression, trauma-related disorders, bipolar disorder, and schizophrenia that are common among people involved in drug treatment. Mental illness can be a barrier to recovery by elevating the risk for relapse and complicating the task of providing effective treatment.

Over 20 million adults in the U.S. have a diagnosable alcohol or drug disorder1, including a growing number of persons who are addicted to pain medication, other opioids, or heroin2. Among personswith substance abuse problems, 38 percent, or approximately eight million have a co-occurring major mental disorder1. The most common co-occurring mental illnesses that cause functional impairment include major depression, trauma-related disorders (e.g., Post-Traumatic Stress Disorder; PTSD), bipolar disorder, and psychotic disorders such as schizophrenia. In comparison to others in substance abuse treatment, persons who have mental disorders are more likely to be homeless, to relapse, to drop out of treatment, to be arrested, and to have a variety of other chronic health disorders (e.g., Hepatitis, HIV, TB)3. The majority of these individuals are not engaged in mental health services.1 Many end up in the criminal justice system, which has become the public health system of last resort for many marginalized populations.4 Persons who have co-occurring disorders often languish in jails or prisons without adequate treatment, and experience worsening of the mental disorders.

There are several common myths about mental disorders that serve as barriers to effective treatment services. It is important to debunk these myths, and to make certain that we address these misperceptions in staff training, academic programs in addiction studies, and public awareness campaigns about the need for behavioral healthcare services in the community. Here are several potentially damaging myths about mental illness:

  1. Those who have mental illness are prone to violence. Stories in the popular media have certainly contributed to the myth that mental illness leads to violence. In fact, persons who have mental disorders are far more likely to be victims of violence than to commit acts of violence against others.5 Overall, mental illness is associated with only a small increase in the risk for arrest and violence.6 Among those in drug treatment who have mental illness, only alcohol use is a predictor of violence against others.5
  2. Persons with mental illness can’t be effectively treated in substance abuse treatment programs. If substance abuse treatment programs excluded persons with a history of mental illness, there would be few persons left to treat. In reality, persons with co-occurring disorders have been effectively treated in all different types of settings, including outpatient and residential drug treatment programs. We recognize that specialized approaches are needed for those with severe mental disorders, particularly those that provide an integrated approach7 to address the intertwined nature of the co-occurring disorders.
  3. Mental disorders can’t be treated unless a person is abstinent or sober. Many treatment programs refuse admission to those who are actively using alcohol or other drugs. Although active users present challenges in any treatment setting, it is important to engage persons in treatment as rapidly as possible, particularly those who have co-occurring disorders, and who are at high risk for relapse, recurrence of mental health symptoms, and arrest. We also know that ignoring substance use disorders can undermine mental health treatment, and that underlying problems (e.g., cravings, physical/psychological dependency) will continue. While skills-based treatment may not be initially helpful for persons who are actively using, treatment can focus on drug testing, strengthening motivation, establishing relationships with treatment staff and peer support networks, and reducing exposure to high risk situations for relapse.
  4. It is important to determine which disorder is “primary” and to begin by treating that disorder. Clinicians have sometimes attempted to identify a “primary” disorder, for example by determining whether mental or substance use disorders appeared first. This approach hinges on the belief that treating the “primary” disorder may resolve the other type of disorder. The resulting sequential treatment does not address the interactive nature of co-occurring disorders and has been found to be ineffective.8


We know that mental disorders are frequently experienced by persons in substance abuse treatment, and also recognize that there are many adverse consequences when we fail to identify and treat the mental disorders. For example, persons with co-occurring mental disorders don’t fare well in traditional mental health or substance abuse treatment programs, and have high rates of dropout, relapse, and arrest. Thus, one of the important challenges for the addiction treatment field is to accurately identify mental disorders, so that specialized services can be provided.

How do we create an effective screening process to identify these disorders? If we recognize the widespread nature of co-occurring mental disorders, the first step in identifying these disorders is to establish universal screening for mental disorders in our substance abuse programs. This means providing mental health screening in all settings in which addiction treatment is provided, including outpatient and residential treatment programs, detoxification programs, crisis stabilization units, and jails and prisons.

A second step is to implement brief standardized screening instruments that are evidence-based, with demonstrated reliability and validity for use with substance-involved populations. Universal screening for mental disorders should, at minimum, include a general screening instrument for major mental disorders. Instruments such as the Mental Health Screening Form – III (MHSF-III), the MINI screen, and the Correctional Mental Health Screen (CMHS), are examples of evidence-based general-purpose screens for mental disorders.3 These screens require approximately 5-8 minutes to administer, don’t require significant training, and are easily scored.

Another recommended area for universal screening is identification of trauma-related disorders such as PTSD, given the high rates of these disorders among substance-involved populations. An example of an evidence-based trauma screen is the Post-Traumatic Checklist for DSM-5 (PCL-5), developed by the Veterans Administration.3 The PCL-5 requires about 10 minutes to administer, is available without charge, and has demonstrated validity with substance-involved populations. Other commonly used screens help to identify risk for suicide and motivation for treatment. For persons scoring above a designated threshold on the various mental health screening instruments, further assessment should be provided by a trained clinician to verify the presence of one or more mental disorders, to determine the scope and severity of the disorders, and to develop a treatment plan to address the disorders.

[1] Han, B., Compton, W.M., Blanco, C., & Colpe, L.J. (2017). Prevalence, treatment, and unmet treatment needs of US adults with mental health and substance use disorders. Health Affairs, 36(10), 1739-1747.

[2] Johns Hopkins Bloomberg School of Public Health and the Clinton Foundation (2017). The opioid epidemic: From evidence to impact.

[3] Peters, R.H., Rojas, E., & Bartoi, M.G. (2016). Screening and assessment of co-occurring disorders in the justice system, 3rd Edition. Delmar NY: SAMHSA’s National GAINS Center for Behavioral Health and Justice Transformation.

[4] Peters, R.H., Wexler, H.K., & Lurigio, A.J. (2015). Co-occurring substance use and mental disorders in the criminal justice system: A new frontier of clinical practice and research. Guest Editorial. Psychiatric Rehabilitation Journal, 38(1), 1-6.

[5] Havassy, B.E., & Mericle, A.A. (2013). Recent violence among persons entering short-term residential mental health and substance abuse treatment. Journal of Dual Diagnosis, 9, 222–227.

[6] Skeem, J., Steadman, H., & Manchak, S. (2015). Applicability of the risk-need-responsivity model to persons with mental illness involved in the criminal justice system. Psychiatric Services, 66(9), 916–922.

[7] Drake, R. E., Mueser, K. T., Brunette, M. F., & McHugo, G. J. (2004). A review of treatments for people with severe mental illnesses and co-occurring substance use disorders. Psychiatric Rehabilitation Journal, 27(4), 360-374.

[8] Horsfall, J., Cleary, M., Hunt, G. E., & Walter, G. (2009). Psychosocial treatments for people with co-occurring severe mental illnesses and substance use disorders (dual diagnosis): A review of empirical evidence. Harvard Review of Psychiatry, 17(1), 24–34.


Roger H. Peters, Ph.D. serves as Spectrum Health Systems’ Senior Research Advisor. Currently, he is a professor in the Department of Mental Health Law and Policy at the University of South Florida, where he has been a faculty member since 1986. Dr. Peters has also served as Principal Investigator and Director for numerous grant projects, including a NIDA P30 Research Core Center award to establish the USF Center on Co-Occurring Disorders, Justice, and Multidisciplinary Research (CJM Center). In addition, he was the chair and co-editor of the SAMHSA/CSAT Treatment Improvement Protocol (TIP) #44 on “Substance Abuse Treatment for Adults in the Criminal Justice System” and lead author of the monograph, “Screening and Assessment of Co-Occurring Disorders in the Justice System” (3rd edition) which was published by SAMHSA in 2016.

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