Deep Sleep in Older Adults

Inclusion Criteria

• Fluent English speaker and reader.
• Capable of providing one's own informed consent.

• As determined by validated, abbreviated phone-based remote Montreal Cognitive Assessment (MoCA) testing score of ≥18, which is the score that separates Mild Cognitive Impairment (MCI) from Alzheimer's Disease and Related Dementia (ADRD).
• Age 55+ years old (inclusive) at enrollment. a. As self-reported on screening survey and later verified in video appointment (e.g. Zoom Health)
• If residing in a community residence (such as a retirement community) in which a Medical Director designates living status categories, then the participant must be Independent Living status (or equivalent).

• As self-reported on screening survey
• Insomnia Severity Index score ≥15 (i.e., at least "clinical insomnia," that is "moderate-to-severe") - but if recruitment is slow then the investigators will recruit with ISI score ≥11 "mild-to-severe").

a. As self-reported on the ISI screening survey

• Willing to refrain from initiating new therapeutic interventions (e.g. medication; behavioral) that are not a part of this study protocol for issues pertaining to sleep for the duration of study participation.

a. By self-report

• Willing to maintain any existing physician-directed pharmacologic intervention for issues pertaining to sleep for the duration of study participation.

a. By self-report

• Has a residence with WIFI.

a. By self-report

• Normal hearing with or without a hearing aid.

a. By self-report

• Difficulty falling asleep, staying asleep, or waking too early, occurring at least 3 nights/week for 3+months, causing significant daytime distress/impairment (e.g., fatigue, poor focus, mood issues), despite adequate sleep opportunity, and not better explained by another sleep disorder or substance.

• By Sleep Condition Indicator [SCI]

Exclusion Criteria

• Illicit drug use in the past month (except for marijuana because it is legal in many States, and the investigators are recruiting nationwide).

a. As self-reported on screening survey. Marijuana usage will be tracked via self-report and examined as a moderator.

• Diagnosed serious mental health disorder.

• Specifically, psychosis or bipolar depression, severe major depression, moderate to high risk of suicide, dementia
• As self-reported on screening survey
• Currently or recent engaged (past 1-year) in evidence-based psychotherapy for Insomnia (e.g., CBTi), in addition to ever receiving a full course of CBTi:

a. By self-report

• Cohabitating with a current or previous participant in this study.

a. This criterion is to avoid cross-contamination of study condition awareness, if two cohabitating individuals are randomized into different study arms.

• Initiation of any psychological treatment in the last 3-months.
• A highly irregular schedule (e.g. shift work) that would prevent adoption of intervention strategies, as evaluated through the Shift Work Disorder Index.
• Previous exposure to the SleepSpace software.
• Medical conditions that are exacerbated by sleep restriction.
• Planned major surgery during the trial.