Antidepressants available in Japan for older people with major depressive disorder: A systematic review and meta-analysis

Aim: To update the major depressive disorder (MDD) treatment guidelines of the Japanese Society of Mood Disorders, we conducted a systematic review and pairwise meta-analysis of double-blind, randomized, placebo-controlled trials of available antidepressants in Japan for older adults with MDD. Methods: Outcome measures included response rate (primary), improvement in depressive symptom scale score, remission rate, all-cause discontinuation, discontinuation due to adverse events, and at least one adverse event. A random-effects model was used to calculate the risk ratio (RR) and standardized mean difference (SMD) with a 95% confidence interval (95% CI). Results: Nine double-blind, randomized, placebo-controlled trials (n = 2145) were identified. No study has been conducted in Japan. Our meta-analysis included the following antidepressants: duloxetine, escitalopram, imipramine, sertraline, venlafaxine, and vortioxetine. Antidepressants have significantly higher response rates than placebo (RR [95% CI] = 1.38 [1.04, 1.83], p = 0.02). Antidepressants outperformed placebo in terms of improving depressive symptom scale score (SMD [95% CI] = −0.62 [−0.92, −0.33], p < 0.0001). However, antidepressants were associated with a higher discontinuation rate due to adverse events (RR [95% CI] = 1.94 [1.30, 2.88], p = 0.001) and a higher incidence of at least one adverse event (RR [95% CI] = 1.11 [1.02, 1.21], p = 0.02) compared to placebo. The groups did not differ significantly in terms of remission rate or all-cause discontinuation. Conclusions: Our meta-analysis concluded that treatment with antidepressants available in Japan is only weakly recommended for moderate to severe MDD in older adults.