The comparable PTSD symptom findings also highlight the significance
of the DSM criterion A of PTSD (i.e., presence of a traumatic
event). There has been considerable discussion of criterion A in the
recent literature (e.g., Kilpatrick et al., 2009), including proposed
changes that remove the requirement that a traumatic event be
accompanied by a reaction of fear, helplessness, and horror in the
next version of the DSM (Frueh et al., 2010). In the present study,
the presence of a criterion A defined trauma was the only symptom
that separated participants with MDD from participants with PTSD.
Participants with MDD that did not meet criterion A for a traumatic
event could not be diagnosed with PTSD on the CAPS, even though
they reported similar PTSD symptom severity on the PCL-C. This suggests
that any loosening of DSM criterion A for PTSD may result in
even higher comorbidity between the two disorders.