What is the impact of comorbidity on treatment outcomes?
Some studies have shown that clients with comorbid mental health disorders have poorer treatment outcomes [67, 89, 91]. There are, however, a growing number of studies that have clearly demonstrated that clients with comorbidity benefit as much as those without comorbid conditions in terms of their AOD use, general physical and mental health, and functioning – even those with severe mental health disorders [66, 92-95]. However, while both those with and without comorbid conditions follow a similar course in terms of their treatment outcomes (i.e., both groups improve), those with comorbid conditions continue to drink or use more, be in poorer physical and mental health, and display poorer functioning following treatment. These findings indicate that AOD services and AOD workers do exceptionally well at treating AOD use (despite the poorer clinical profile described in the previous section) and its associated disability, but that the disability associated with the comorbid condition remains.