Investigating the link between subjective sleep quality, symptoms of PTSD, and level of functioning in a sample of trauma-affected refugees

Study Objectives: To examine whether baseline sleep quality is associated with baseline symptoms of posttraumatic stress disorder (PTSD) and level of functioning and whether baseline sleep quality and improvement of sleep quality are specific predictors of change in PTSD symptoms and level of functioning. Methods: Data were derived from a four-armed randomized controlled superiority trial (N = 219 trauma-affected refugees). All four groups received treatment as usual consisting of a 10-12 months bio-psycho-social treatment program with an additional differential treatment component added to each arm. We performed bivariate correlation analyses, multiple linear regression analyses, and mediation analyses to examine associations between baseline sleep quality, change in sleep quality, and treatment response for PTSD symptoms and level of functioning. Results: Baseline sleep quality correlated with symptoms of PTSD (r = 0.33) and level of functioning (r = 0.15). Baseline sleep quality, improvement of sleep quality, and improvement of general well-being were predictors of treatment response for symptoms of PTSD and level of functioning when controlling for age, gender, and baseline symptoms of PTSD and depression. Conclusions: We found that good sleep quality at baseline and improvement of sleep quality were predictors of PTSD treatment response. However, treatment response was more closely associated with improvement in general well-being. The results indicate that the effect of improved sleep quality was partly mediated by a more general mental state improvement. Further research is needed to differentiate if a selected subgroup of patients may profit from sleep-enhancing treatment.