Alcohol dependence: 8 RCTs (n=487) involving patients without co-morbid depression and 9 RCTs (n=359) involving patients with co-morbid depression were included. The study duration ranged from 1 to 24 weeks.
Cocaine dependence: 14 RCTs (n=876) involving patients without co-morbid depression and 5 RCTs (n=226) involving patients with co-morbid depression were included. The study duration ranged from 2 to 13 weeks.
Nicotine dependence: 18 RCTs (n=5,633) were included. In 11 of the studies, the sample included some patients with a history of major depression. The study duration ranged from 7 to 52 weeks.
Opioid dependence: 6 RCTs (n=396), all involving patients with co-morbid depression, were included. The study duration ranged from 4 to 12 weeks.
Five studies on alcohol dependence, eight on cocaine dependence and one on nicotine dependence were excluded during the review process because their quality score was two or less; these were not included in the numbers of studies given above (see Numbers of Studies Included).
Alcohol dependence: the use of antidepressants (SSRI or other) did not significantly affect any outcome except for a positive effect of non-SSRIs on depressive symptoms in patients with co-morbid depression (3 studies; OR 4.15, 95% CI: 1.35, 12.75).
Cocaine dependence: the use of antidepressants (SSRI or other) did not significantly affect any outcome except for a positive effect of non-SSRIs on cocaine consumption in patients without co-morbid depression (7 studies; OR 1.85, 95% CI: 1.06, 3.22).
Nicotine dependence: the use of bupropion (8 studies; OR 2.07, 95% CI: 1.42, 3.01) and nortriptyline (4 studies; OR 2.69, 95% CI: 1.47, 4.91) had a significant positive effect on abstinence from nicotine. The overall effect of antidepressant treatment was also positive (17 studies; OR 1.78, 95% CI: 1.36, 2.33).
Opioid dependence: the use of non-SSRIs in patients with co-morbid depression had a significant positive effect on reduction of opioid consumption (2 studies; OR 3.65, 95% CI: 1.10, 12.16), but the use of antidepressants did not reduce depressive symptoms.