Comparing Home-Based Digital Treatments for Insomnia.

There are three intervention groups. 1. THIM Participants in the THIM group will self-select a night convenient for them to undergo treatment, i.e., a night with minimal activities the following day to mitigate the daytime effects of sleep restriction (typically on the weekend). Participants will connect the device (posted to them by study researchers) to their internet-enabled smartphone via an anonymous account created for them by the study researchers and follow the THIM app instructions to set up the device. Participants will then lie down in bed and attempt to fall asleep at their habitual bedtime (calculated from pre-treatment sleep diaries, likely around 10pm) while wearing THIM on the index finger of their dominant hand. THIM will emit subtle vibratory stimuli approximately every 30 seconds to which the participant must respond by tapping their finger against their thumb. When the participant fails to respond to the stimuli, typically shortly after entering light sleep, THIM will infer that they have fallen asleep and subsequently wake the participant by emitting a high intensity vibration. The participant will remain awake for a 2-minute break before THIM instructs them to attempt to fall asleep again on the next trial. This process (known as Intensive Sleep Retraining) will continue overnight for 10 hours (likely around 8am). Study researchers will be available via phone and email. After the treatment ends in the morning, participants will remain awake (confirmed by sleep tracker data) until at least one hour before their habitual bedtime the night after (likely around 9pm). They will be strongly encouraged to not drive, operate heavy machinery or make important decisions until they feel recovered. After the anticipated long recovery sleep, participant will be advised to maintain a consistent sleep phase (between 10:00 PM and 8:00 AM) and sleep opportunity (maximum nine hours) in the six weeks following treatment. 2. Sleep Healthy Using The Internet (SHUTi) Participants will receive a subscription from study researchers to the established six-module self-guided online program. The content of the six modules are as follows: 1) overview of insomnia and setting treatment goals, 2) sleep restriction therapy and sleep habits, 3) stimulus control therapy, 4) sleep education, 5) cognitive therapy, 6) relapse prevention. Participants will complete each weekly module over six weeks on their computers (30-60 minutes per module) and implement the activities provided in these modules within this time, such as mildly restricting their sleep in week 2. Study researchers will be available via phone and email. 3. The combination (THIM followed by SHUTi) Participants in the combined treatment group will undergo THIM as described above during the first week of SHUTi (module 1), prior to the administration of sleep restriction therapy (module 2) and stimulus control therapy (module 3). They will then undergo the remaining 3 modules as planned (all 6 modules will be completed). Consequently, their time commitment is still six weeks in duration. Study researchers will be available to all participants via phone and email for technical support, to monitor safety (via study measures, e.g., sleep diaries, weekly questionnaires), and to follow up on attrition of study measures. Study researchers will not play an active role in treatment.