Effect of Adjunctive Simvastatin on Depressive Symptoms Among Adults With Treatment-Resistant Depression: A Randomized Clinical Trial.

Importance: Immune-metabolic disturbances have been implicated in the pathophysiology of major depressive disorder and may be more prominent in individuals with treatment-resistant depression (TRD). Preliminary trials suggest that lipid-lowering agents, including statins, may be useful adjunctive treatments for major depressive disorder. However, no adequately powered clinical trials have assessed the antidepressant efficacy of these agents in TRD. Objective: To assess the efficacy and tolerability of adjunctive simvastatin compared with placebo for reduction of depressive symptoms in TRD. Design, Setting, and Participants: This 12-week, double-blind, placebo-controlled randomized clinical trial was conducted in 5 centers in Pakistan. The study involved adults (aged 18-75 years) with a Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) major depressive episode that had failed to respond to at least 2 adequate trials of antidepressants. Participants were enrolled between March 1, 2019, and February 28, 2021; statistical analysis was performed from February 1 to June 15, 2022, using mixed models. Intervention: Participants were randomized to receive standard care plus 20 mg/d of simvastatin or placebo. Main Outcomes and Measures: The primary outcome was the difference between the 2 groups in change in Montgomery-Åsberg Depression Rating Scale total scores at week 12. Secondary outcomes included changes in scores on the 24-item Hamilton Rating Scale for Depression, the Clinical Global Impression scale, and the 7-item Generalized Anxiety Disorder scale and change in body mass index from baseline to week 12. C-reactive protein and plasma lipids were measured at baseline and week 12. Results: A total of 150 participants were randomized to simvastatin (n = 77; median [IQR] age, 40 [30-45] years; 43 [56%] female) or placebo (n = 73; median [IQR] age, 35 [31-41] years; 40 [55%] female). A significant baseline to end point reduction in Montgomery-Åsberg Depression Rating Scale total score was observed in both groups and did not differ significantly between groups (estimated mean difference for simvastatin vs placebo, -0.61; 95% CI, -3.69 to 2.46; P = .70). Similarly, there were no significant group differences in any of the secondary outcomes or evidence for differences in adverse effects between groups. A planned secondary analysis indicated that changes in plasma C-reactive protein and lipids from baseline to end point did not mediate response to simvastatin. Conclusions and Relevance: In this randomized clinical trial, simvastatin provided no additional therapeutic benefit for depressive symptoms in TRD compared with standard care. Trial Registration: ClinicalTrials.gov Identifier: NCT03435744.

Minocycline and celecoxib as adjunctive treatments for bipolar depression: a multicentre, factorial design randomised controlled trial.

BACKGROUND: Several small studies suggest that the adjunctive use of anti-inflammatory agents might improve depressive symptoms in bipolar disorder. However, there are few well designed, appropriately powered clinical trials assessing the efficacy of these novel treatment strategies. We aimed to assess the efficacy of adjunctive minocycline or celecoxib in this setting. METHODS: This double-blind, 12-week, randomised, placebo-controlled trial was done in four outpatient psychiatric clinics in Pakistan. Eligible participants were adults (aged 18-65 years) with DSM-5 bipolar disorder (type I or II) and a major depressive episode. In a 2 × 2 factorial design, participants were randomly assigned (1:1:1:1) to receive either active minocycline plus active celecoxib, active minocycline plus placebo celecoxib, placebo minocycline plus active celecoxib, or placebo minocycline plus placebo celecoxib. The primary outcome was the mean change from baseline to week 12 in score on the 17-item Hamilton Depression Rating Scale (HAMD-17), assessed in all randomised participants (missing data were imputed and assumed to be missing at random). The trial was registered with ClinicalTrials.gov, NCT02703363. FINDINGS: 266 (17%) of 1542 patients assessed between May 1, 2016, and March 31, 2019, were randomly assigned to receive minocycline plus celecoxib (n=68), minocycline plus placebo (n=66), celecoxib plus placebo (n=66), or placebo plus placebo (n=66). From baseline to week 12, depressive symptoms as per HAMD-17 reduced in all four groups (from 24·5-25·2 to 11·3-12·8), but these reductions did not differ significantly between the groups. In terms of main effects, reductions in HAMD-17 did not differ for patients treated with minocycline (mean adjusted difference vs non-minocycline 1·48 [95% CI -0·41 to 3·36]; p=0·123) or for celecoxib (mean adjusted difference vs non-celecoxib -0·74 [-2·61 to 1·14]; p=0·443). Rates of serious adverse effects did not differ between groups (31 participants had a manic switch, two self-harmed, and one died in a motor vehicle accident). INTERPRETATION: We found no evidence that minocycline or celecoxib was superior to placebo for the treatment of bipolar depression. This large trial casts doubt on the potential therapeutic benefits of adjunctive anti-inflammatory drugs for the acute management of bipolar depression. FUNDING: Stanley Medical Research Institute.