17_Dual Diagnosis and Addiction
Substance use Disorders and co-occurring Psychiatric Disorders
Dual diagnosis is the term normally used to describe people with both substance use problems and
psychiatric problems (Fitzgerald, 1997). Dual disorders are fairly common among substance misusing
clients.
In the USA, The Epidemiological Catchment Area Study (ECA; Robins and Regier, 1991) found that
37% of individuals with alcohol use disorders, and 53% of individuals with drug use disorders, met
lifetime criteria for a psychiatric illness. The ECA study also found high rates of substance abuse
among clients who met criteria for these specific psychiatric disorders (primary diagnosis):

Antisocial Personalities

Bipolar

Schizophrenia
85% also with substance abuse
61% also with substance abuse
47% also with substance abuse
Other common areas of co-morbidity with substance dependence:

Personality Disorders (e.g. Narcissistic or Borderline Personality Disorder); Anxiety and Mood
Disorders; Obsessive-Compulsive disorders.
Effects on the client population of dual diagnosis
Specific effects on the client will depend on the interactions between the type and severity of the
disorder and the client’s personality, coping mechanisms and personal competencies.
Research has confirmed a higher rate of problems for people who have co-morbidity, than for those
who possess a single disorder: “Co-morbid conditions interact synergistically to debilitate,
compromise recovery, and shorten lives” (White, 2001, p51).
Meta-analysis of 100 studies (Drake and Mueser, 2000) found higher rates of the following problems
amongst dual disordered clients:

severe financial problems
17_Dual Diagnosis and Addiction

unstable housing and homelessness

medication non-compliance

relapse to either disorder

violence

legal problems

incarceration

depression and suicide

sexually transmitted disorders and HIV infection
Compared to those who had only a psychiatric disorder, those with dual disorders were found to
have:

More diagnoses

Higher rates of psychiatric re-hospitalisation

Higher rates of suicide

Higher rates of homicide

Lower rates of treatment entry and completion

Lower rates of successful transition from in-patient to ambulatory care

Lower rates of ambulatory care attendance
(Daley and Marlatt, 2006).