Long-term effectiveness of collaborative depression care in older primary care patients with and without PTSD symptoms

Abstract

Objective: Depressed patients with comorbid post-traumatic stress disorder (PTSD) are more functionally impaired and may take longer to respond to depression treatment than patients without PTSD. This study examined the long-term effects of PTSD on depression severity, treatment response, and health care costs among older adults.

Methods: Patients were recruited from 18 primary care clinics in five states. A total of 1801 patients aged 60 years or older with major depression or dysthymia were randomized to Improving Mood Promoting Access to Collaborative Treatment (IMPACT) collaborative care or usual care. The study included 191 (10.6%) subjects who screened positive for PTSD. Depression severity, assessed by the Hopkins Depression Symptom Checklist, was used to estimate depression-free days (DFDs) over 24 months. Total health care costs included inpatient, outpatient, and pharmacy costs.

Results: Depressed patients with PTSD had higher depression severity than patients without PTSD symptoms at baseline. Over 2 years, intervention patients with PTSD symptoms had relatively the same benefits from collaborative care (99 more DFDs than usual care patients) as patients without PTSD (108 more DFDs than usual care) (p = 0.85). Total health care costs did not differ significantly for depressed patients with and without PTSD symptoms.

Conclusion: Depressed older adults with PTSD symptoms were more depressed at baseline, but collaborative care (compared to usual care) produced similar improvements in depression severity in both groups. This reduction of depression symptoms was observed for up to 12 months after the intervention ended, suggesting that long-term improvements in depression are possible with collaborative care in patients with and without PTSD symptoms.

Figure 1

Depression score over 2 years by PTSD screen status and intervention group Notes: Scores on the SCL-20 ranged from 0–4. IV= intervention UC= Usual Care

Figure 2

Depression-free days over two years by PTSD screen status (Unadjusted)