Clinically significant pain was reported by half of the women with CSA presenting for depression treatment at a community mental health center, suggesting it is common in this population. Women with high-pain entered treatment with significantly more severe depression than those with low-pain. This gap was not bridged over the course of treatment. Although depression improved in both pain groups, women with high-pain remained moderately depressed at treatment completion. Baseline emotional functioning was comparable in the high-and low-pain groups, but women with high-pain were significantly less improved in this domain than women with low-pain.
Our goal in this study was to focus on the common and clinically significant symptom of pain, and determine its association with treatment outcomes. This was an effectiveness study in a “real life” clinic using a naturalistic design and a complex patient population. Our findings strongly suggest that clinicians should take note of pain problems among their patients with depression and CSA, carefully monitor their responses to depression treatment, and consider the need for adjunct treatments that specifically target pain. Due to the limited scope of this paper, we could not determine if comorbid physical and mental disorders, medication use, or other related variables account for some of the pain effects. We cannot assert a causal relationship between pain and depression treatment response. It is a possibility that pain is a marker, rather than a cause, of risk for poor outcomes. PTSD and borderline personality disorder, for example, when co-occurring with pain could detract from depression treatment response, either directly or by potentiating the negative effects of pain. More research designed to elaborate our understanding of pain’s role in depression treatment response is warranted.
We can only speculate as to why pain is associated with more severe depression among this sample of depressed women with CSA. In contrast, depression severity did not differ between high and low pain interference among patients in primary care [10
]. One possibility is that women with CSA histories and pain experience a biologically discrete variant of depression that requires a different treatment approach [22
]. For example, pain may serve as a marker for more significant depressive severity, more advanced progression of depression, or more refractory depression in women with CSA histories. Alternatively, the comorbidity of CSA, depression, and pain may occur more often among a sub-group of vulnerable patients. Another possible explanation is that depressed patients with CSA may have greater pain sensitivity. The consistent finding across self-report (BDI) and clinician-report (HRDS) suggests that this association is not simply a response bias.
A basic premise of IPT is that improving function will in turn alleviate depression. Yet for the women with high-pain, there was a lack of improvement in emotional function despite a decrease in depression severity following treatment. Several possibilities might explain this finding. IPT, like most psychosocial treatments for depression, tends to target the emotional symptoms of depression, perhaps neglecting physical symptoms and daily functioning [23
]. Greater emphasis on function may be indicated in the treatment of individuals with pain and may lead to greater improvements in depression. Alternatively, among patients with CSA, depression, and pain, functional improvement may follow mood improvement or not improve to the same degree as among patients with CSA and depression only. Treatment of higher intensity or longer duration or interdisciplinary treatments may be indicated when pain is present. Perhaps pain and its sequelae distract patients from effectively engaging in treatment and following treatment recommendations that might improve function [9
]. It is not uncommon for patients to receive contradictory recommendations for managing their pain and depression. For example, rest may be prescribed in response to a pain episode, but may exacerbate depressive symptoms through increased isolation and decreased pleasurable activities. It may be beneficial to design psychotherapy treatments to conceptualize and target both symptoms of pain and depression, as well as the functional contexts in which they occur.
A primary limitation of this study is the lack of comparison to another standardized depression treatment. We do not know if the findings are IPT-specific, or generalizable to other treatments. Pain is extremely challenging to measure due to its implicit subjectivity and individual variability. Additionally, we cannot report on the role of pain duration, pain location, number of pain sites, or medical diagnoses. Our relatively small sample, consisting of two related studies, and the use of retrospective data analyses, mitigate the robustness of our conclusions. The novel treatment sample, which includes minority and low-income individuals, rigorous methodology, and clinically relevant findings, however, warrant the tentative conclusions drawn based on these preliminary findings.