Longitudinal analysis of the suicidal behaviour risk in short-term placebo-controlled studies of mirtazapine in major depressive disorder

OBJECTIVE: To examine suicidal behaviour risk in the short-term placebo-controlled studies of mirtazapine in Major Depressive Disorder (MDD). METHOD: Longitudinal Generalized Estimating Equations analyses were performed on pooled data from 15 placebo-controlled, randomized, double-blind, short-term trials of mirtazapine, using the suicide item scores from the Hamilton Depression Rating Scale (HAMD) as a proxy outcome measure for suicidality risk. RESULTS: The overall analysis using the convention that a patient is at risk if the HAMD suicide item score is > or =3, and excluding patients at risk at baseline, demonstrated a statistically significantly lower risk for mirtazapine- compared to placebo-treated patients on the HAMD (odds ratio mirtazapine versus placebo 0.38; 95% confidence interval 0.21-0.66; P= 0.0008). CONCLUSION: Our results based on pooled data from 15 placebo-controlled, short-term studies of mirtazapine in MDD using the suicide item scores from the HAMD as a proxy outcome measure for suicidality risk, demonstrate that mirtazapine was associated with statistically significantly lower suicidality risk compared to placebo.