This study is the first randomised control trial to rigorously test a sequential approach to treating comorbid PTSD and major depressive disorder.
Findings from a trial of 52 patients undergoing three types of treatment regime - using only Cognitive Processing Therapy (CPT), using Behavioural Activation Therapy (BA) with some CPT, or CPT with some BA - found that a combined treatment protocol resulted in meaningful reductions in PTSD and depression severity, with improvements maintained at six-month follow-up investigations.
"We sought to examine whether a protocol that specifically targeted both PTSD and comorbid depression would benefit those with this dual diagnosis compared with a solely PTSD-focused protocol," says Flinders PTSD research expert Professor Reg Nixon.
"With some qualifications, the answer to this question is yes in the case of CPT and BA."
The findings - "Comorbid posttraumatic stress disorder and major depressive disorder: The usefulness of a sequential treatment approach within a randomised design," by Samantha Angelakis, Nathan Weber, and Reg Nixon - has been published in the Journal of Anxiety Disorders.
It found that the reductions in depressive symptoms that occur when PTSD symptoms are targeted early in treatment are consolidated when closely followed with behavioural activation.
"Although the findings need to be replicated, our observation that when depression was targeted before PTSD that those individuals did not quite have as good an outcome as those in the other conditions indicates there might be a cost to delaying or putting off targeting PTSD symptoms over depressive symptoms," says Professor Nixon.
"Facing one's trauma is understandably very difficult, but our findings suggest that trying to 'ease' into this work and working on depression first might not in fact help clients as much as people would expect."
The researchers also noted that CPT alone, without any modifications, still demonstrated positive outcomes in this comorbid sample
"Our clinical view at this time is that when individuals with PTSD and MDD present for PTSD treatment, CPT should be delivered first."
Those with higher levels of depression showed greater change from treatment than those with lower levels of depression. Although symptoms tended to remain higher in these individuals after treatment than those with lower levels of depression, the findings indicated that those with high levels of depression still benefited from therapy.