Background: This study examined the effectiveness of antidepressants in a group of elderly depressed outpatients by assessing depression prevalence and recording adverse events over time.
Method: A prospective practice-based observational study (1991-1994) included consecutive outpatients at least 65 years of age with a DSM-III-R diagnosis of major affective disorder and who were prescribed antidepressant medications. Depressive symptoms were examined over time (stage 1 = 0 to 2 months; stage 2 = 2 to 6 months; stage 3 = 6 months to 2 years) with the Montgomery-Asberg Depression Rating Scale (MADRS). The cutoff scores of MADRS <18 and MADRS > or =18 were used in survival statistics. Adverse events were recorded systematically.
Results: A total of 213 patients were seen over 2677 visits (mean +/- SD age = 75.5+/-6.1 years). MADRS scores for 85.8% of patients declined to below 18 within the first 2 months of antidepressant treatment. MADRS scores were above 18 for 37.3% of patients after 6 months and for 37.1% after 2 years. The mean time to decline in MADRS scores to below 18 in stage 1 was 36.1 days, and there was a significant difference between the antidepressant classes (log rank = 8.3, df = 3, p = .04), with tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs)/reversible inhibitors of monoamine oxidase A (RIMAs) having shorter times to response. The mean time to reach scores above cutoff during stage 2 was 144.3 days (log rank = 5.7, df = 3, p = .13) and during stage 3, 538.6 days (log rank = 9.8, df = 3, p = .02). Patients receiving TCAs and MAOIs/RIMAs had longer durations of MADRS scores below cutoff during stage 3 than those taking atypical antidepressants and selective serotonin reuptake inhibitors. All antidepressant classes reported similar adverse event profiles.
Conclusion: This study systematically examined antidepressant effectiveness in a prospective design. TCAs and MAOIs/RIMAs were shown to be superior in effectiveness during 2 of the 3 treatment stages.