RecruitingBehavioural interventionBehavioral Insomnia Treatment in Mild Traumatic Brain InjuryThis is a single site, two-armed random controlled trials (RCT) comparing six sessions of Cognitive Behavioral Therapy for Insomnia (CBT-I) with four sessions of Brief Behavioral Therapy for Insomnia (BBT-I) in service members with comorbid insomnia and prolonged postconcussive symptoms present for at least 3 months after Mild Traumatic Brain Injury (mTBI).