Accelerated Treatment for Co-occurring Insomnia, Nightmares, and PTSD

Inclusion Criteria: 1. Defense Enrollment Eligibility Reporting System (DEERS) eligible active-duty military personnel or veteran, 18-65 years old. 2. Ability to speak and read English. 3. Clinically significant PTSD symptoms (CAPS-5 \> 25 with at least one Intrusion symptom and at least one Avoidance symptom). 4. Clinically significant symptoms of insomnia disorder (Structured Clinical Interview for Sleep Disturbance DSM-5 (SCISD) Insomnia Criteria are met and Insomnia Severity Index (ISI) \> 11). 5. Nightmares \> 1 monthly (as reported on the SCISD). 6. Willing to refrain from new behavioral health or medication treatment for issues pertaining to PTSD, sleep, and nightmares during study participation. Exclusion Criteria: 1. Current suicide or homicide risk meriting crisis intervention. 2. Inability to comprehend the baseline screening questionnaires. 3. Unwilling to remain abstinent from alcohol during therapy sessions. 4. Serious mental health symptoms, such as mania, psychosis, alcohol or substance use disorders warranting immediate clinical attention based on interviewer assessment and clinical judgement. 5. Currently engaged in evidence-based psychotherapy for PTSD (e.g., Prolonged Exposure Therapy, Cognitive Processing Therapy, Written Exposure Therapy) or insomnia or nightmares (e.g., Cognitive Behavioral Therapy for Insomnia or Nightmares). 6. Pregnancy, as determined by self-report, because pregnancy can adversely affect sleep outside of PTSD, insomnia, and nightmares. 7. Working duty shifts ending later than 21:00 or starting before 05:30 more than 2 times per month.