Sleep Restriction Therapy (SRT) Protocols

SRT is the mechanical engine of CBT-I. By drastically limiting the amount of time you are allowed to spend in bed, it builds a massive homeostatic sleep pressure (Process S in the Two-Process Model). This pressure forces the brain to consolidate sleep, eliminating middle-of-the-night awakenings (WASO).

The Baseline Assessment

Before restricting sleep, a patient must maintain a sleep log for 1-2 weeks. From this log, the clinician calculates the average Total Sleep Time (TST). The initial Time in Bed (TIB) prescription is set exactly equal to the average TST.

Example: If you spend 9 hours in bed, but only sleep 5.5 hours, your new prescribed TIB is 5.5 hours.

Clinical Safety Floor: Time in Bed is never restricted below 5.0 to 5.5 hours, regardless of baseline TST, to prevent dangerous levels of daytime cognitive impairment.

The Titration Process

Every week, the patient calculates their Sleep Efficiency (SE = TST / TIB). The prescription is adjusted based on this number. You can automate this math using our CBT-I Titration Tool.

• SE > 90%: Increase TIB by 15-30 minutes. (Sleep is consolidated, you have earned more time).
• SE 85% - 90%: Maintain current TIB.
• SE < 85%: Decrease TIB by 15-30 minutes (respecting the 5.5-hour floor).

The "Fix the Wake Time" Rule

To anchor the circadian rhythm, the wake time must remain identical 7 days a week. All TIB adjustments are made by altering the bedtime. If your wake time is 6:00 AM and your TIB is 6 hours, your bedtime is midnight. No exceptions.