Prevalence and impact of co-occurring psychiatric disorders on outcomes from a private hospital drug and alcohol treatment program

Aim: This naturalistic study was designed to assess the prevalence and impact of co-occurring mental disorders in 104 adults (52% male) admitted to a private hospital drug and alcohol treatment program in Brisbane, Australia. Method: Psychiatric diagnoses made by the participants' admitting psychiatrists were collected by chart audit. Measures of substance use, dependence and mood were obtained by a program psychologist on participants' admission to the hospital, and during a follow-up interview conducted by the second researcher an average of 8.5 months after participants' discharge. Results: Ninety-two per cent of the sample was diagnosed with at least one mental disorder; most commonly Major Depressive Disorder (57%), Generalised Anxiety Disorder (20%) and Borderline Personality Disorder (16%). Having a concurrent mood, anxiety or personality disorder was not significantly related to either program attendance or outcomes on substance related self-report measures. Only depression symptoms at follow-up were associated with significantly fewer per cent days abstinent in the past 30 days. Conclusion: While co-occurring mental disorders are highly prevalent in this sample, the disorders conferred no significant disadvantage for patients undergoing treatment for substance abuse. However, depression symptoms should be addressed in the period after discharge in order to ensure positive longer-term outcomes