A Cochrane review [Abstract] 1 included 51 RCTs with a total of 3603 patients. Forty-four studies with 3372 patients with physical illness and depression contributed data to the efficacy analyses. The trials were conducted in stroke (n=11), HIV/AIDS (n=7), Parkinson's disease (n=6), cancer (n=4), chronic obstructive pulmonary disease (COPD, n=3), diabetes (n=3), myocardial infarction (n=3), renal failure (n=2) and one in each of rheumatoid arthritis, brain injury, asthma, coronary artery disease, chronic heart failure, epilepsy and chronic prostatitis. There were also 3 trials with mixed diagnoses. Depression included major depression, adjustment disorder and dysthymia. SSRIs and tricyclic antidepressants vs. placebo were used in majority of the trials. Pooled data for the primary outcome, response to treatment, provided an OR of 2.33 (95%CI 1.80 to 3.00; 25 studies, 1674 patients) favouring antidepressants. Antidepressants were also more efficacious at the other time-points. At 6-8 weeks number-needed-to-treat (NNT) for antidepressants was 6. At 4-5 weeks, 9-18 weeks and >18 weeks NNT was 7. At 6-8 weeks, fewer patients receiving placebo dropped out compared to patients treated with an antidepressant. Dry mouth and sexual dysfunction were more common in patients treated with an antidepressant.
Comment: The quality of evidence is downgraded by study quality (inadequate allocation concealment) and inconsistency (heterogeneity in patients and treatments). The quality of evidence is upgraded by large magnitude of effect.
Another Cochrane review [Abstract] 2 included 10 RCTs with a total of 709 patients. Seven studies were conducted prior to 2000 and 7 studies had predominantly men. Seven studies assessed antidepressants vs. placebo, two compared different antidepressant classes and one had three arms comparing two antidepressant classes with placebo. There was a moderate improvement in depression when assessed with the Hamilton Depression Rating Scale (HAM-D) score as a continuous outcome (SMD 0.59, 95% CI 0.21 to 0.96; 6 studies, n = 357). However, there was no evidence of improvement when this was assessed with HAM-D score as a dichotomized outcome (RR 1.10, 95% CI 0.89 to 1.35; 5 studies, n = 434) or Clinical Global Impression of Improvement (CGI-I) score (RR 1.28, 95% CI 0.93 to 1.77; 4 studies, n = 346). There was little to no difference in the proportion of study dropouts between study arms (RR 1.28, 95% CI 0.91 to 1.80; 4 studies, n = 306). Sexual dysfunction was reported commonly in people receiving SSRIs. People receiving tricyclic antidepressants (TCAs) frequently reported anticholinergic adverse effects such as dry mouth and constipation. There was no evidence of a difference in follow-up CD4 count at study termination (MD -6.31 cells/mm3, 95% CI -72.76 to 60.14; 3 studies, n = 176). There were few studies comparing different antidepressant classes. There was some evidence that mirtazapine resulted in a greater improvement in depression compared to an SSRI (MD 9.00, 95% CI 3.61 to 14.39; 1 study, n = 70); however, this finding was not consistent for all measures of improvement in depression for this comparison.
Comment: The quality of evidence is downgraded by study quality (inadequate allocation concealment) and inconsistency (heterogeneity in patients and time periods for studies). The quality of evidence is upgraded by large magnitude of effect.
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