Comorbid Depression and Other Predictors of PTSD Severity in Urban Public Transit Employees.

The purpose of the study was to determine whether post traumatic stress disorder (PTSD) with Major Depressive Disorder (MDD) among urban public transit employees who were exposed to a workplace traumatic event is associated with greater PTSD severity over the 6-month follow-up period compared to PTSD without MDD, and also to identify predictors of PTSD severity among these employees. Information about Axis-I diagnosis and PTSD severity were collected from the SCID-I and the Modified PTSD Symptom Scale (MPSS) respectively. PTSD without MDD (N = 29) and PTSD with MDD (N = 37) groups were not significantly different in terms of PTSD severity. The severity of depression (p = 0.01), female (p = 0.01), non-Caucasian (p = 0.01), perceived high workplace related stress (p = 0.02), and history of lifetime trauma (p = 0.01) were significantly associated with greater PTSD severity after controlling other variables. This study highlights the importance of modifiable variables for reducing PTSD severity after a workplace traumatic event in transit employees.