Antidepressants often are used to treat depressive symptoms in patients with dementia, but this practice is not backed by strong evidence, according to a systematic review published in the Cochrane Database of Systematic Reviews.
“On the only measure of efficacy for which we had high-quality evidence (depression rating scale scores), antidepressants showed little or no effect,” reported Robert Dudas, MD, PhD, of the University of Cambridge (England), and his associates. “The evidence on remission rates favored antidepressants but was of moderate quality, so future research may find a different result.”
For the review, a total of 10 studies – which altogether included of 1,592 patients – were examined, of which 8 included enough information to enter into analyses about antidepressant efficacy, Dr. Dudas and his associates reported. The average age in the studies was 75 years, and study participants had mild or moderate dementia.
After 6-13 weeks, little difference in depression symptom rating scale scores was found between antidepressant- and placebo-treated groups (standardized mean difference, –0.10 points; 95% confidence interval, –0.26 to 0.06). Similar results were found after 6-9 months (SMD, 0.59 points; 95% CI, –1.12 to 2.30).
Antidepressants did not significantly improve response rates (odds ratio, 1.71; 95% CI, 0.80-3.67) but were associated with a higher remission rate (OR, 2.57; 95% CI, 1.44-4.59). After 6-13 weeks, no difference was found between antidepressants and placebo on performance of daily activities (SMD, –0.05; 95% CI, –0.36 to 0.25) or in cognition (mean difference of 0.33 in Mini-Mental State Examination scores; 95% CI, –1.31 to 1.96).
In addition to experiencing no significant improvement in depression symptoms, patients who received antidepressants were more likely to drop out of treatment than were those receiving placebo (OR, 1.51; 95% CI, 1.07-2.14) and to experience at least one adverse event (OR, 1.55; 95% CI, 1.21-1.98). Adverse events more likely to occur in patients receiving antidepressants included dry mouth (OR, 1.80; 95% CI, 1.23-2.63) and dizziness (OR, 2.00; 95% CI, 1.34-2.98).
“ There is a need for well-conducted, randomized, controlled trials, using scales validated in older people with depression and dementia, of modern, frequently used drugs and sufficient sample sizes that would allow a study of treatment response and detailed adverse event profile according to dementia etiology and severity and depression severity,” the investigators concluded.
The study was supported by several entities, including the Cambridgeshire and Petersborough NHS Foundation Trust, Collaborations for Leadership in Applied Health Research and Care, and the National Institute for Health Research, all in the United Kingdom. Dr. Dudas and his associates declared no conflicts of interest.
SOURCE: Dudas R et al. Cochrane Database Syst Rev. 2018 Aug 31. doi: 10.1002/14651858.CD003944.pub2.