Minocycline as an adjunct for treatment-resistant depressive symptoms: A pilot randomised placebo-controlled trial

• Published in: Journal of psychopharmacology (Oxford) 2017-09, Vol.31 (9), p.1166-1175
• Main Authors: Husain, Muhammad I, Chaudhry, Imran B, Husain, Nusrat, Khoso, Ameer B, Rahman, Raza R, Hamirani, Munir M, Hodsoll, John, Qurashi, Inti, Deakin, John FW, Young, Allan H
• Format: Article
• Language: English
• Subjects: Antibiotics; Antidepressants; Anxiety; Check lists; Clinical trials; Inflammation; Mental depression; Minocycline; Pharmacology; Randomization; Studies
• ISSN: 0269-8811; 1461-7285
• DOI: 10.1177/0269881117724352

Background: Evidence suggests that anti-inflammatory medication may be effective in the treatment of depressive symptoms. In this study, we aimed to investigate whether minocycline added to treatment as usual (TAU) for 3 months in patients with treatment-resistant depression will lead to an improvement in depressive symptoms. Methods: Multi-site, 12-week, double-blind, placebo-controlled, pilot trial of minocycline added to TAU for patients suffering from DSM-5 major depressive disorder, whose current episode has failed to respond to at least two antidepressants. The primary outcome measure was mean change in Hamilton Depression Rating Scale (HAMD-17) scores from baseline to week 12. Secondary measures were the Clinical Global Impression scale (CGI), Patient Health Questionnaire-9 (PHQ-9), the Generalised Anxiety Disorder scale (GAD-7) and EuroQoL (EQ-5D) quality-of-life questionnaire. Side-effect checklists were also used. Minocycline was started at 100 mg once daily (OD) and increased to 200 mg after 2 weeks. Results: A total of 41 participants were randomised, with 21 in the minocycline group and 20 in the placebo group. A large decrease in HAMD scores was observed in the minocycline group compared to the placebo group (standardised effect size (ES) –1.21, p < 0.001). CGI scores in the minocycline group also showed a large improvement compared with placebo (odds ratio (OR): 17.6, p < 0.001). PHQ-9, GAD-7 and EQ-5D total showed more moderate improvements (ES ~ 0.4–0.5). Conclusion: The findings indicate that adjunctive minocycline leads to improvement in symptoms of treatment-resistant depression. However, our findings require replication in a larger sample. Trial Registration: ClinicalTrials.gov identifier: NCT02263872, registered October 2014.