Inclusion Criteria:
1. Active duty Sailors, activated Reservist Sailors: The study focuses on the treatment in Sailors. Therefore, eligible participants must be active duty Navy, or activated Reservist Navy. Military personnel from other branches, Veterans, other DoD beneficiaries, and civilians are not eligible for the study.
2. Diagnosis of chronic insomnia; PSQI score \> 9: The study focuses on the treatment of insomnia. Therefore, eligible participants must have received a diagnosis of chronic insomnia by the study evaluators.
3. History of TBI: The study focuses on the treatment of insomnia in Sailors with TBI. Therefore, eligible participants must have a confirmed history of TBI by the study evaluators.
4. Stable for at least 8 weeks on psychotropic and hypnotic medications: ADSMs currently using prescribed psychotropic and hypnotic medications will be eligible to participate in the trial if they have been on the same medication(s) and at the same dose(s) for at least 8 weeks and there are no expected changes over the course of the acute intervention phase (i.e., up to 6 weeks). Medication usage and changes will nevertheless be tracked prospectively and be considered in the analytical plan should changes occur. To ensure that the three groups are equivalent in composition, the randomization process will be stratified by the use/non-use of psychotropic and hypnotic medication.
5. Stable on continuous positive airway pressure therapy for sleep apnea for at least 90 days and usage of 4 hours or more per night, for at least 70% of the nights: ADSM with comorbid with sleep disordered breathing (SDB) will be eligible to participate in the trial if they are currently stable on continuous positive airway pressure therapy for at least 4 weeks. It is increasingly recognized that insomnia and SDB are often comorbid in military samples56-60. Therefore, exclusion of participants with comorbid SDB would significantly compromise the external validity of the proposed clinical trial. However, SDB requires independent treatment and, if untreated or under-treated comorbid sleep disorder, may be exacerbated by sleep restriction or stimuli control.
6. Own a smart device: Participants in all three treatment delivery conditions will use the COAST app to complete the electronic daily sleep logs and study assessments. Thus, ownership of a smartphone will be required.
Exclusion Criteria:
1. Unable to give informed consent: Individuals who are unable to give informed consent cannot be enrolled in the study. A decisional capacity to consent test, which will be submitted for approval to the Institutional Review Board (IRB), will be used to determine whether a potential participant has the capacity to provide consent on their own behalf.
2. Severe TBI: Individuals with severe TBI will be excluded from this study due to complex medical needs which may require close medical attention and pose safety concerns with regards to completing the study procedures.
3. Potential alcohol use disorder: Individuals who meet diagnostic criteria for current alcohol or substance use disorders will be excluded as these conditions may perpetuate insomnia and daytime impairments and pose safety concerns with regards to completing the study procedures.
4. Inability to comprehend or read English: Participants with demonstrated inability to comprehend or read English will not be eligible for the study. The intervention is highly dependent on understanding the treatment rationale and adhering to behavioral sleep modification instructions. The treatment materials for in-person CBT-I and for CBT-I delivered via digital health platform are only available in English at this time and is the treating clinician's only spoken language. An inability to comprehend or read English limits engagement in CBT-I, and adversely impacts the risk/benefit ratio of participating in the study. Because the study is limited to ADSMs of the United States, it is expected that nearly all potential patients are proficient in reading, writing, speaking, and understanding English, even is English is not their primary language.
5. Serious mental health diagnosis such as bipolar disorder or psychosis; or seizure disorder: Participants who have been previously diagnosed with psychotic or bipolar disorders, or who endorse symptoms of these conditions during the psychiatric assessments, will not be included in the trial because the mild and transient sleep deprivation induced by sleep restriction and stimulus control may exacerbate symptoms and increase the risk of participating in the study. Similarly, individuals with untreated or treatment-resistant seizure disorder will be excluded because seizures may be precipitated or exacerbated by sleep restriction.
6. Hypersomnia disorder: Potential participants that have been diagnosed with hypersomnia that can be exacerbated by the transient and mild sleep deprivation induced by sleep restriction and stimulus control will not be included in the trial as the interventions pose greater safety risks for these participants.
7. Working rotating shifts or requiring that the ADSM report to work earlier than 6am: Potential participants working rotating shifts or who are required to work earlier than 6am will not be included in the trial. Waking up at the same time every day, including on weekends, is a critical aspect of both sleep restriction and stimulus control procedures. Working rotating shifts prohibits participants from adhering to this critical treatment guideline. Being required to work earlier than 6am similarly presents a challenge to waking up at the same time every day, especially on non-workdays when waking earlier than 6am is an unnatural wake time
