Abstract
Evidence describing the association between sleep quality and trauma-focused therapy is mixed. This secondary analysis of a primary care sample examined whether (a) baseline sleep quality moderated posttraumatic stress disorder (PTSD) symptom severity over time across groups receiving different doses of cognitive processing therapy (CPT) and (b) sleep quality improved over time with CPT. Participants were 227 adults who screened positive for PTSD and were participating in a clinical trial comparing two models of PTSD treatment delivery in primary care. The Pittsburgh Sleep Quality Index (PSQI) and PTSD Checklist for DSM-5 (PCL-5) were used to assess sleep disturbance and PTSD symptom severity, respectively. Multiple linear regression was used to assess whether baseline PSQI scores moderated 12-month PCL-5 scores across CPT dosage groups (0 sessions: 51.1%, 1-7 sessions: 31.7%; ≥ 8 sessions [adequate dose]: 17.2%) and whether PSQI scores differed by group at 12-month follow-up. Post hoc analyses examined changes in PCL-5 sleep disturbance items. Baseline sleep disturbance did not moderate the effect of CPT on PTSD severity among participants with an adequate CPT dose, p > .112. Sleep quality improved with adequate dose, B = -2.63, SE = 0.75, p < .001. Differences in change scores across groups for PCL-5 Item 2, F(2, 435) = 11.34, and Item 20, H(2) = 32.04, indicated that participants with an adequate CPT dose had greater reductions in trauma-related sleep symptoms than those who received 0-7 sessions, ps < .001. Residual post-CPT sleep impairment despite adequate PTSD improvement warrants further interventions.