Simvastatin as an adjuvant therapy to fluoxetine in patients with moderate to severe major depression: A double-blind placebo-controlled trial

Statins have been shown to decrease depressive symptoms in certain groups of patients, an effect that is mostly attributed to their anti-inflammatory and neurotransmitter modulatory potentials. We aimed to investigate the antidepressant effects of simvastatin as an adjuvant therapy in patients with moderate to severe depression. In this double-blind placebo-controlled clinical trial, 48 patients were randomly allocated to receive simvastatin or placebo as an adjunct to fluoxetine for six weeks. Patients were evaluated with the Hamilton Depression Rating Scale (HDRS) at baseline and weeks 2, 4 and 6. Probable clinical and laboratory adverse events were also monitored and compared between the two groups. Simvastatin-treated patients experienced significantly more reductions in HDRS scores compared to the placebo group by the end of the trial (p=0.02). Early improvement and response rates were significantly greater in the simvastatin group than the placebo group (p=0.02 and p=0.01, respectively) but remission rate was not significantly different between the two groups (p=0.36). No serious adverse event was reported during this trial. In conclusion, simvastatin seems to be a safe and effective adjuvant therapy for patients suffering from major depressive disorder. However, more confirmatory studies are warranted.