The Impact of Mindfulness Training on Posttraumatic Stress Disorder Symptoms, Subjective Sleep Quality, and Objective Sleep Outcomes in Police Officers

OBJECTIVE: Sleep disturbances cooccur with posttraumatic stress disorder (PTSD) and are often correlated with PTSD severity. Previous research has shown that sleep problems mediate the relationship between PTSD and negative physical and mental health outcomes but has relied on self-reported sleep quality. We tested the effects of mindfulness training—previously shown to improve sleep quality and reduce PTSD symptoms—on subjective and objective sleep metrics and relationships with reduced PTSD symptoms. METHOD: Following baseline data collection in 114 law enforcement officers, we randomly assigned participants to either an 8-week mindfulness training group or a waitlist control group. We repeated assessments immediately posttraining and at 3-month follow-up. Self-reported PTSD symptoms and subjective sleep quality were measured at each visit with the PTSD checklist and Pittsburgh Sleep Quality Index (PSQI), respectively. Participants also wore a Fitbit Charge 2 continuously over the course of a 4- to 6-day work week following each visit, from which we extracted two distinct objective sleep metrics: total minutes of sleep and sleep efficiency. RESULTS: At baseline, PTSD symptoms were correlated with PSQI scores but not objective Fitbit metrics. Relative to waitlist, mindfulness training led to improved subjective sleep quality and reduced PTSD symptoms. Reduced PTSD symptoms mediated the improvement in subjective sleep quality following mindfulness training. Neither objective sleep metric demonstrated improvements following mindfulness training, nor did these metrics mediate reduced PTSD symptoms. CONCLUSIONS: This study provides evidence linking improved subjective sleep quality, but not objective sleep markers, to reductions in PTSD symptoms following mindfulness training. Clinical Impact Statement: Prior work has demonstrated improvements in subjective sleep quality and reduced posttraumatic stress disorder (PTSD) symptoms following mindfulness training, but relationships with objective sleep metrics have been largely untested. In this study of trauma-exposed individuals with significant sleep disturbances, we found that improvements in subjective sleep quality following a mindfulness intervention were mediated by reduced PTSD symptoms, whereas objective sleep metrics showed no change in response to mindfulness training. This highlights the value of subjective reports of sleep quality which, compared to objective, real-world indicators of sleep quality, provide unique insight into etiology and recovery from PTSD.