Sleep compression is a behavioral technique derived from the principles of Cognitive Behavioral Therapy for Insomnia (CBT-I). This method systematically reduces the amount of time an individual spends awake in bed, thereby aiming to consolidate fragmented sleep and improve its overall quality. By temporarily shortening the total time in bed (TIB), the therapy works to increase the body’s natural drive for sleep, which helps to re-associate the bed with quick, sound slumber. Sleep compression is designed to reverse the common insomnia pattern of spending extended periods in bed tossing and turning, which can condition the mind to associate the bedroom with wakefulness and frustration. The approach does not seek to permanently reduce the total amount of sleep an individual receives, but rather to make the existing sleep period more efficient.
Sleep Compression Versus Sleep Restriction Therapy
The key distinction between sleep compression and the related sleep restriction therapy (SRT) lies in the initial reduction of the time in bed (TIB). Both interventions share the goal of increasing sleep efficiency by limiting the period spent in bed to the actual time spent asleep. However, SRT typically mandates a significant and immediate reduction in TIB, often setting the sleep window to as little as five to five-and-a-half hours, regardless of the individual’s average sleep time. This abrupt change can cause notable daytime sleepiness and is sometimes difficult for patients to tolerate initially.
Sleep compression, conversely, employs a gentler, more incremental reduction strategy. The initial TIB is set closer to the patient’s current average total sleep time, often based on a two-week sleep diary average. This less aggressive starting point makes sleep compression a favored alternative, particularly for older adults or those sensitive to the effects of temporary sleep deprivation. The gradual reduction helps mitigate side effects like excessive daytime fatigue, promoting better adherence. While SRT can produce faster initial improvements, sleep compression offers a more comfortable path to the same eventual goal of consolidated sleep.
Step-by-Step Implementation
Implementing sleep compression begins with establishing an accurate baseline of the current sleep pattern, which requires keeping a detailed sleep diary for one to two weeks. This log tracks metrics like bedtime, time spent falling asleep, number and duration of awakenings, and final wake-up time. The average total time spent asleep (TST) is then calculated from this diary to determine the starting Time in Bed (TIB).
The initial prescribed TIB is generally set equal to the calculated average TST, or sometimes the TST plus a small buffer, such as 30 minutes. Once this TIB duration is established, a rigid, fixed schedule must be maintained, meaning the designated bedtime and wake time remain the same every night, including weekends. For example, if the average TST is six hours, the individual may be instructed to stay in bed only during a six-hour window.
This fixed schedule is paired with stimulus control instructions, which strictly limit the use of the bed and bedroom to only sleep and sex. If sleep does not occur within about 20 minutes, the individual is instructed to leave the bed and engage in a quiet, non-stimulating activity until they feel sleepy again. Adhering to this rigid schedule reinforces the association between the bed and rapid, consolidated sleep.
Monitoring Progress and Adjusting the Schedule
The success of the sleep compression schedule is tracked using a specific metric known as Sleep Efficiency (SE). This metric is calculated by dividing the Total Sleep Time (TST) by the Time in Bed (TIB) and multiplying the result by 100 to get a percentage. For example, if a person spends eight hours in bed but only sleeps for six hours, their SE is 75%.
The goal of the therapy is to increase this SE percentage, consolidating the sleep within the restricted time window. The schedule is then modified based on the average SE calculated from the previous week’s sleep diary data. If the average SE is consistently above a target threshold, typically 85% to 90%, the TIB is gradually extended to allow for more sleep. This extension is cautious and incremental, usually by a small amount such as 15 minutes, which can be added to either the bedtime or the wake time. Conversely, if the SE falls below the target range, the TIB is either held steady for another week or slightly reduced again to further increase sleep pressure.
Suitability and Safety Considerations
Sleep compression is most appropriate for individuals who have chronic, psychophysiological insomnia, especially those who spend a disproportionate amount of time awake in bed. People whose primary sleep problem is fragmented sleep—waking up frequently or for long periods during the night—tend to respond well to the technique.
The therapy should not be attempted without professional medical guidance, especially for individuals with certain pre-existing conditions. Contraindications include untreated sleep disorders like obstructive sleep apnea, whose symptoms could be worsened by sleep deprivation. Individuals with conditions such as bipolar disorder or epilepsy are also advised against independent use, as restricted sleep can sometimes trigger manic episodes or seizures. People whose occupations require consistently high levels of alertness, such as commercial drivers, must proceed with caution due to the temporary increase in daytime sleepiness that can occur early in the treatment.