Depression often goes hand-in-hand with Post Traumatic Stress Disorder (“PTSD”). And that can ruin the sufferer’s quality of life. A recent scientific study focused on Veterans with comorbid Depression and PTSD. The report, entitled Impact of comorbid depression on quality of life in male combat Veterans with posttraumatic stress disorder, is based on a “large meta-analysis composed of 57 studies, across both military and civilian samples.” What did the researchers find? That there is a comorbitiy rate of 52% for Veterans with PTSD and depression. That’s pretty high.
There isn’t a definitive explanation for the high prevalence of depression with PTSD. But, “[r]esearch has shown that PTSD has a deleterious impact on Veteran life quality, as Veterans with PTSD report increased rate of unemployment due to disability, decreased social and occupation-related functioning, and lower life satisfaction.”
More information can be found through the embedded hyperlink (see above). But, here is a taste of the article’s introduction:
Research has demonstrated that for Veterans with posttraumatic stress disorder (PTSD), depression is a highly comorbid condition. A recent large meta-analysis composed of 57 studies, across both military and civilian samples, reported a comorbidity rate of 52 percent. The underlying reason for this high degree of comorbidity is unclear. One theory postulates that the disorders represent differing symptom manifestations of an underlying stress construct, a position supported by the common diatheses of the two disorders. Researchers have also highlighted the lack of specificity of PTSD’s symptoms as a possible cause, and a recent study with a Veteran sample found that a subset of PTSD symptoms related to numbing loaded more strongly on a depression factor than on the PTSD factor. Furthermore, in that study, individuals endorsing these numbing-related symptoms reported significantly more comorbid PTSD and depression and significantly higher depressive symptom severity.
While there is no definitive explanation for the high degree of depression comorbidity observed in individuals with PTSD, there is reason to suspect that it may be associated with reduced Veteran quality of life, which has been conceptualized as a person’s physical, mental, and social well-being. Research has shown that PTSD has a deleterious impact on Veteran life quality, as Veterans with PTSD report increased rates of unemployment due to disability, decreased social, and occupation-related functioning, and lower life satisfaction. There is also literature documenting the significant negative impact of depression on quality of life. Similar to PTSD, depression has been associated with financial problems and decreased life satisfaction.
Several studies suggest that individuals with PTSD who also have comorbid depression have worse quality of life than those with PTSD alone. Research in non-Veteran samples has found that PTSD and depression comorbidity is associated with significantly worse major role functioning than PTSD alone and significantly worse social and occupational functioning than is associated with only PTSD or neither disorder. The few studies conducted with Veterans have produced a similar pattern of findings. In a study with Israeli Veterans of the 1982 Lebanon War, individuals with comorbid PTSD, depression, and anxiety reported worse psychosocial functioning than individuals with only PTSD. Additionally, in a large sample of Korean war Veterans, individuals with comorbid PTSD and depression reported poorer satisfaction with their physical and psychological health, social relationships, and environment compared with Veterans with only PTSD or only depression. These studies provide preliminary evidence that PTSD and comorbid depression can have a significantly more detrimental impact on Veteran quality of life than PTSD alone. However, further research is needed to elucidate this impact, given the multifaceted nature of quality of life.
Quality of life has been operationalized in a variety of ways and using various measures, with researchers advocating the importance of assessing both subjective life satisfaction as well as more objective indices. In their review of the quality of life literature for Iraq and Afghanistan Veterans, Schnurr and colleagues adopted a framework focusing on subjective and objective indices across three domains: social-material conditions, functioning, and satisfaction. Social-material quality of life includes areas such as employment, income, and marital status. Functioning involves an individual’s role performance, or their ability to function at work, in relationships, and in different life domains. Satisfaction is concerned with individual well-being and subjective appraisal of life quality. This tripartite approach shares similarities to other conceptualizations of quality of life, as well as the World Health Organization’s definition of the construct. Existing studies have examined the impact of comorbid PTSD and depression on these domains, but more research is needed exploring these relationships in Veteran samples.
Additionally, further empirical investigation is needed to disentangle the unique contributions of PTSD and depression to the decreased quality of life associated with comorbidity of the disorders. One study involving Operation Iraqi Freedom (OIF)/Operation Enduring Freedom (OEF) combat Veterans found that PTSD and depression both independently contributed to mental-health-related quality of life, with depression predicting more variance than PTSD. In another study of Veterans, depressive symptoms had a significant impact on satisfaction-related quality of life, although PTSD was not significantly related. Likewise, in a sample of Veterans with PTSD, researchers found that depression predicted overall physical-health-related quality of life, while PTSD did not, although analysis of the quality of life subscales provided a more nuanced picture of the findings. While depressive symptoms predicted physical and role functioning scales, both depressive symptoms and PTSD independently predicted general health and bodily pain scales, and depression and PTSD interacted to predict vitality and social functioning scales. Taken together, the existent research suggests that PTSD and depression make unique contributions to decreased quality of life, but that depression exerts a stronger influence. Further research is needed, however, especially to examine possible differences in the impact of depression and individual PTSD symptom clusters. Studies have found that various PTSD symptom clusters are negatively associated with quality of life, perhaps most notably the PTSD numbing symptom cluster, identified in the emotional numbing four-factor structure and later incorporated into the structure of the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 diagnostic criteria for PTSD. Because the numbing cluster shares significant overlap with depression, understanding its relationship with quality of life and how it resembles or differs from that of the other symptom clusters, is essential to understanding the unique contributions of PTSD and depression to decreased quality of life.
The purpose of the current study was to examine the impact of PTSD and comorbid depression on social-material, functioning, and satisfaction-related quality of life domains in a sample of male combat Veterans with PTSD. We used the DSM-IV PTSD symptom clusters of the emotional numbing model, which share significant overlap with the new DSM-5 diagnostic criteria. For all domains where comorbid depression was significantly associated with poorer quality of life, we explored the unique contributions of PTSD symptom clusters and depression. While we initially defined depression by categorical diagnosis of major depressive disorder (MDD), we also conducted post hoc analyses operationalizing depression using the Beck Depression Inventory-II (BDI-II), which provided a dimensional measure of depressive symptoms.
We predicted that individuals with comorbid PTSD and MDD would have significantly worse quality of life than individuals with PTSD alone across all social-material, functioning, and satisfaction-related quality of life domains. Given the research connecting a variety of PTSD symptom clusters to poorer quality of life, we also predicted that both PTSD symptom clusters and comorbid MDD would uniquely influence each quality of life domain.