Conflict of Interest Disclosure
There is nothing to declare.
Abstract
Objective: Emerging preclinical and clinical evidence suggests a potential role of nicotinic acetylcholine receptors in the pathophysiology of depression. Several clinical trials have investigated the efficacy of nicotinic acetylcholine receptor antagonists in treatment-resistant depression. We performed this meta-analysis to investigate whether nicotinic acetylcholine receptor antagonists significantly improve symptoms in patients with major depressive disorder who have an inadequate response to standard antidepressant therapy.
Methods: A comprehensive literature search identified 6 randomized controlled trials. These 6 trials, which included 2067 participants, were pooled for this meta-analysis using a random-effects model.
Results: Nicotinic acetylcholine receptor antagonists failed to show superior efficacy compared to placebo in terms of the mean change in the Montgomery-Asberg Depression Rating Scale (MADRS) score (mean difference = -0.12 (95% CI= -0.96 to 0.71); response rate (risk ratio (RR)= 0.92 (95% CI= 0.83 to 1.02); and remission rate (RR= 1.01 (95% CI= 0.83 to 1.23)).
Conclusion: This meta-analysis failed to confirm preliminary positive evidence for the efficacy of nicotinic acetylcholine receptor antagonists in treatment-resistant depression. Further studies investigating the efficacy of various alternative treatment strategies for treatment-resistant depression will help clinicians to better understand and choose better treatment options for these populations.
Keywords: Nicotinic antagonist, treatment resistance, major depressive disorder.