Traumatic experiences as vulnerability factors for mood disorders (MDs) remain unknown. The present study examined the potential differences of traumatic experiences amongst inpatients with mood disorders and between inpatients with mood disorders and non-patients. Of the participants assessed with Traumatic Experiences Checklist (TEC) (mean age = 31.12 ± 13.70), 50.8% had MDs, and 49.2% were non-patients (n = 29). The group of thirty individuals with Structured Clinical Interview for DSM-IV (SCID)-diagnosed MDs included 19 patients with major depression disorder (32.2%), 5 with Depressive Disorder Not Otherwise Specified (8.5%), 6 with Bipolar I Disorder, Most Recent Episode Depressed (10.2%).

Of the patients 76.7% endorsed having experienced at least three TEs in their life time, of the non-patients 86.2% reported less than three TEs in their life time. Patients had significantly (t = 4.96, p < 0.001) more TEs (M = 6.20 ± 2.98) than the control group (M= 2.38 ± 2.94), the distinction was specially relevant on the severity of emotional trauma (M = 7.80 ± 8.74; t = 3.71, p < 0.001). Amongst MDs, there were not statistical differences. Only major depression disorder was distinct from the control group in what concerns total TEC (p < 0.001), specially owing to trauma occurred under 6 years of age.

These findings are generally supportive of the role of trauma, specially trauma that took place in infancy, on major depression disorder, suggesting the need for consideration of traumatic experiences on the treatment of this mood disorder.