Comorbid mental disorders and substance use disorders: epidemiology, prevention and treatment

Chapter 1: Responding to comorbid mental disorders and substance use disorders

Page last updated: 2003

Maree Teesson and Heather Proudfoot

Comorbidity of mental disorders and substance use disorders is common. Furthermore, comorbidity is often associated with poor treatment outcome, severe illness course, and high service utilisation. This presents a significant challenge with respect to the identification, prevention and management of people with comorbid disorders. The unmet need for treatment within this group is considerable, the lack of research is unacceptable and the person with comorbid mental disorders and substance use disorders is often left to fall in the gap between the relevant services.

The issue of comorbidity between mental disorders and substance use disorders is demanding attention from researchers, clinicians and policy makers. Despite this demand there is very little guidance to date regarding best practice for individuals with more than one disorder. Controlled trials of treatment for comorbid disorders are urgently needed, so that we can deliver services to this population on a sound evidence base. Given the frequency and the impact of comorbidity on both individuals and the community, training of health practitioners should routinely incorporate what we already know about the assessment and management of co-occurring mental disorders and substance use.

The questions are clear:

  1. How common is comorbidity? Which are the most common and most disabling comorbidities from both an individual and public health perspective using the epidemiological evidence?

  2. How would you prevent and treat comorbidity? What is the research evidence on the prevention and treatment of the most common and most disabling comorbidities?

  3. What are the implications of comorbidity for service delivery? How do we improve our response to comorbidity and what is current good practice in treatment and service system models?
The following chapters aim to assist with answers to these important questions.