Effect of depression treatment on depressive symptoms in older adulthood: the moderating role of pain.

Objectives: To investigate whether pain severity and interference with normal work activities moderate the effects of depression treatment on changes in depressive symptoms over time in older adults in primary care.

Design: Patient-randomized, clinical trial.

Setting: Multisite: three clinics located in Veterans Affairs Medical Centers.

Participants: Adults aged 60 and older (n=524) who screened positive for depression and participated in the Primary Care Research in Substance Abuse and Mental Health for the Elderly Study.

Intervention: Integrated care versus enhanced specialty referral care.

Measurements: Pain severity, the degree to which pain interferes with work inside and outside of the home, and depressive symptoms were examined at baseline and 3, 6, and 12 months.

Results: Intention-to-treat analyses revealed that both treatment groups showed reduced depressive symptoms over time, although self-reported pain moderated reductions in depressive symptoms. At higher levels of pain severity and interference with work activities, improvements in depressive symptoms were blunted. Furthermore, pain interference appeared to have a greater effect on depressive symptoms than did pain severity; in individuals with major depression, pain interference fully accounted for the moderating effects of pain severity on changes in depressive symptoms over time.

Conclusion: Pain and its interference with functioning interfere with recovery from depression. Findings highlight the importance of addressing multiple domains of functioning (e.g., physical and social disability) and the degree to which pain and other forms of physical comorbidity may hinder or minimize treatment-related improvements in depressive symptoms.