Do subjective and objective baseline sleep disturbances predict post-traumatic stress disorder treatment response? A secondary analysis of a randomized controlled trial

$\textbf{Background:}$ Sleep disturbances are highly prevalent in individuals with post-traumatic stress disorder (PTSD) and might interfere with trauma-focused treatments by disrupting memory consolidation, extinction and safety learning. However, evidence on the impact of sleep deficits on PTSD treatments remains inconclusive. $\textbf{Objective:}$ This study conducted a secondary analysis of a randomized controlled trial comparing cognitive processing therapy (CPT) and dialectical behaviour therapy for PTSD (DBT-PTSD) in women with PTSD. We examined whether subjective and objective baseline sleep disturbances predicted PTSD symptom reduction after up to 15 months of outpatient treatment, whether depression moderated this relationship, and whether effects differed for CPT and DBT-PTSD. $\textbf{Method:}$ Sleep was assessed in n = 178 women using actigraphy, sleep diaries, and the Pittsburgh sleep quality index (PSQI), applying linear mixed models for each sleep measure. $\textbf{Results:}$ Subjective sleep disturbances as measured in the PSQI did not significantly predict overall treatment outcomes for PTSD (p = .140). Additionally, depressive symptoms did not moderate this relationship (p = .469), and the effect did not differ for CPT and DBT-PTSD (p = .086). The same was found for sleep diary and actigraphy assessments. $\textbf{Conclusions:}$ These findings suggest that sleep disturbances do not hinder the effectiveness of long-term trauma-focused PTSD treatment in women with complex trauma presentations, implying that sleep-specific interventions may not be a prerequisite for initiating trauma-focused treatment in this population.