OBJECTIVES: This pharmacovigilance activity assesses the psychiatric and behavioral safety profile of suvorexant, a recently approved novel orexin receptor blocker indicated for the treatment of insomnia. METHODS: Reports of adverse drug events submitted to the FDA Adverse Events Reporting System (FAERS) between 2014 and 2015 were analyzed to calculate the Empirical Bayes Geometric Mean (EBGM) and 95% confidence interval (EB05-EB95) as disproportionality measures. Safety signals are defined as measures with ≥2.0EB05. Treatment with suvorexant was defined by reported generic name; and psychiatric events were defined by High-Level Group Terms (HLGT) under Psychiatric Disorders System Organ Class hierarchy of MedDRA 18.0 after excluding these HLGT: changes in physical activity; deliria; dementia and amnestic conditions; sexual dysfunction; and communication, developmental, eating, and sleep disorders. RESULTS: Overall, 1598 adverse event reports were submitted for suvorexant during the first postmarketing year, with psychiatric events accounted for 9% (n=141) of all reports (87% from U.S. and 13% from Japan). About 54% of psychiatric cases were women, mean age 54 years (min=20, max=95). Approximately 24% of reported cases were serious, including 2 completed suicides and 6 suicidal attempts (n=4 life-threatening, n=1 resulted in hospitalization, and n=1 resulted in disability). Majority of cases used suvorexant as monotherapy (65%), with mean number of concomitant medications 1.4 (min=1, max=19). The average daily dose of suvorexant was 12 mg, corresponding to 5 mg (4%); 10 mg (64%); 15 mg (15%); and 20 mg (17%). There was disproportional reporting of psychiatric events for suvorexant compared to other medications in the reporting period, albeit did not reach signal threshold (EBGM= 1.75, EB05-EB95=1.52-2.01). CONCLUSIONS: Insomnia treatment with suvorexant may be associated with psychiatric risks. Pharmacoepidemiologic studies are suggested to characterize the benefit-risk profile of suvorexant. Meanwhile, prescribers should evaluate patients for depressive symptoms and behavioral changes before and periodically during therapy.