Post-traumatic stress disorder and depression co-occurrence: Structural relations among disorder constructs and trait and symptom dimensions.

In assessing individuals who have been exposed to trauma, practitioners should recognize that co-occurring PTSD and MDD appears to be best represented as two distinct, yet strongly related constructs. Negative affect may be the shared vulnerability directly influencing both PTSD and MDD; however, in the presence of both PTSD and MDD, low positive affect appears to be more specifically related to MDD and fear of physical sensations to PTSD, which is information that could be used by practitioners in the determination of treatment approach. Overall, these findings are clinically relevant in that they may inform assessment, treatment planning, and ultimately diagnostic classification.