Modified Xiaochaihu Decoction Combined with Mirtazapine in the Treatment of Persistent Depression: A Pilot Randomized Controlled Trial

Background: Western drugs effectively manage persistent depressive disorder (PDD) but are associated with side effects.

Objective: To observe the efficacy and safety of modified Xiaochaihu Decoction combined with mirtazapine in treating PDD.

Methods: Patients with PDD were enrolled at the Naval General Hospital (06/2018-02/2019) and randomized to modified Xiaochaihu Decoction and modified Xiaochaihu Decoction with mirtazapine. The self-rating depression scale (SDS) and traditional Chinese medicine (TCM) scale were assessed at baseline and after 12 weeks. The overall clinical efficacy (primary outcome) and adverse reactions were observed.

Results: Sixty-four participants completed the trial in the combined and control groups (30 and 28), respectively. In controls, the total effective rate was 78.6%, compared with 96.7% in the combined group (=0.035). The scores of the SDS and TCM syndrome scale in the two groups were lower after treatment ( < 0.001) but without difference between groups (=0.077). The combined group showed higher improvement rates regarding insomnia (96.4% vs. 44.0%, < 0.001), bitter taste (90.5% vs. 52.6%, =0.007), languid (72.0% vs. 31.8%, =0.006), and belching/anorexia (100% vs. 52.6%, < 0.001). The combined group showed a higher frequency of adverse events (73.3% vs. 3.6%) ( < 0.001).

Conclusion: Modified Xiaochaihu Decoction combined with mirtazapine effectively treats PDD, and its curative effect is better than that of TCM alone. This trial was registered with https://www.chictr.org.cn/index.aspx/ChiCTR2100048188.