Sleep problems contribute to post-concussive symptoms in service members with a history of mild traumatic brain injury without posttraumatic stress disorder or major depressive disorder

BACKGROUND: Many with a history of mild traumatic brain injury (TBI) experience sleep problems, which are also common symptoms of stress-related and mood disorders. OBJECTIVE: To determine if sleep problems contributed unique variance to post-concussive symptoms above and beyond symptoms of posttraumatic stress disorder/major depressive disorder (PTSD/MDD) after mild TBI. METHODS: 313 active duty service members with a history of mild TBI completed sleep, PTSD, and mood symptom questionnaires, which were used to determine contributions to the Neurobehavioral Symptom Inventory. RESULTS: 59% of the variance in post-concussive symptoms were due to PTSD symptom severity while depressive symptoms and sleep problems contributed an additional 1% each. This pattern differed between those with and without clinical diagnosis of PTSD/MDD. For those with PTSD/MDD, PTSD and depression symptoms but not sleep contributed to post-concussive symptoms. For those without PTSD/MDD, PTSD symptoms and sleep contributed specifically to somatosensory post-concussive symptoms. Daytime dysfunction and sleep disturbances were associated with post-concussive symptoms after PTSD and depression symptoms were controlled. CONCLUSIONS: PTSD symptom severity explained the most variance for post-concussive symptoms among service members with a history of mild TBI, while depression symptoms, daytime dysfunction, and sleep disturbances independently contributed small amounts of variance.