Objective: To examine the impact (if any) of a course of transcranial magnetic stimulation (TMS) on irritability occurring in association with acute major depressive disorder (MDD).

Method: In a naturalistic study, patients with MDD according to DSM-5 criteria were given 20 daily TMS treatments. A visual analogue scale for irritability (VAS-I) was developed. Objective tools included the six-item Hamilton Depression Rating Scale (HAMDS6) and the Clinical Global Impression - Severity (CGI-S).

Results: Fifty patients received 53 courses. Forty-seven courses achieved remission on both HAMD6 and CGI-S and six courses did not achieve remission with either. Irritability significantly reduced when MDD remission was achieved but was unchanged when remission was not achieved.

Conclusion: TMS reduces irritability occurring in association with MDD when this treatment affects MDD remission, but not when remission is not affected.