The influence of depression on treatment for methamphetamine use.

OBJECTIVE

To determine whether the presence of comorbid depression influences response to psychological treatment for methamphetamine use.

DESIGN

Randomised controlled clinical trial.

SETTING AND

PARTICIPANTS

Our study was conducted between 2001 and 2005 at two sites in Australia: the Hunter Region of New South Wales and the city of Brisbane, Queensland. The 214 participants, who were all using methamphetamine at least once a week in the month prior to the study, were self-referred or referred from health services or drug and alcohol clinical services. Participants were divided into two groups based on whether or not they had depressive symptoms at baseline.

INTERVENTIONS: The control group received only a self-help booklet; the two treatment groups received either two or four counselling sessions involving cognitive behaviour therapy and motivational interviewing techniques to manage methamphetamine use.

MAIN OUTCOME MEASURES: Changes in methamphetamine use and depression at 5 weeks and 6 months after baseline.

RESULTS

Over 70% of participants met criteria for depression at baseline, and depression was associated with significantly greater severity of methamphetamine use and related issues. Benzodiazepine use was significantly higher among depressed than non-depressed participants. Reductions in methamphetamine use between baseline and 5 weeks were independently predicted by comorbid depression, in favour of increased change among those with baseline depression. Depressed participants who received three or four counselling sessions showed a significant reduction in depression at 5 weeks. However, reductions in methamphetamine use and depression compared with baseline were no longer evident at 6 months.

CONCLUSIONS

Over the short term, comorbid depression did not negatively affect response to treatment, with some evidence of a dose-response treatment effect for reduction in depression. This was not maintained at 6 months, indicating that methamphetamine-focused treatment may not enable people with comorbid depression to make sustained improvement at the level of their counterparts without depression.

TRIAL REGISTRATION NUMBER: ACTRN12611000355976.