Prospective study of relationship between PTSD, anxiety and depression
Nov 24, 2012
It has long been known that PostTraumatic Stress Disorder (PTSD) can be co-morbid with a number of other disorders, particularly depression and anxiety. However, what the causative processes involved in these relationships has been much less clearly understood. A new study by Angela Nickerson, of Australia's University of New South Wales, and colleagues from the United States, has begun to shed some light on those relationships, at least those occurring after sexual assault [LINK]
In this study, participants were 126 women who had been sexually assaulted in the previous 4 weeks. It was found, using lower level mediation analyses, that changes in PTSD symptoms had a greater impact on changes in depression and anxiety than vice versa. Changes in PTSD symptoms contributed more to changes in scores on measures of depression and anxiety than changes in scores on measures of depression and anxiety contributed to changes in measures of PTSD when time since trauma was considered.
The finding highlights the role of PTSD symptoms in influencing subsequent change in other psychological symptoms. The authors discuss their findings in the context of models detailing the trajectory of psychological disorders following trauma, and clinical implications are considered. The results suggest that symptoms of depression and anxiety develop secondarily to PTSD in trauma survivors. It appears that, not only does PTSD often manifest prior to other psychological disorders as suggested by other studies, but that changes in PTSD symptoms strongly influence changes in comorbid anxiety and depression.
The researchers go on to argue that, in terms of clinical practice implications, it may be most beneficial to first target PTSD symptoms in individuals with comorbid PTSD / depression / anxiety diagnoses in the months following a traumatic event, rather than symptoms of anxiety or depression.
Of particular relevance to the primary focus of this site, there are limitations associated with this study. It only examined psychological symptoms in the acute period following sexual assault, rather than long-term interrelationships between psychological symptoms. Further, only female sexual assault survivors were examined, which limits the generalizability of the findings. However, the study represents the first prospective investigation of the relationship between changes in PTSD and comorbid symptoms of depression and anxiety in women who have been recently sexually assaulted.
The findings underscore the importance of change in PTSD symptoms in influencing subsequent change in symptoms of depression and anxiety, and highlight the potential overall psychological benefits of first targeting symptoms of PTSD in the acute period following sexual assault.