A randomized controlled trial of intensive sleep retraining (ISR): a brief conditioning treatment for chronic insomnia

Abstract

Study objective: To investigate the effectiveness of intensive sleep retraining in comparison and combination with traditional behavioral intervention for chronic primary insomnia.

Participants: Seventy-nine volunteers with chronic sleep-onset insomnia (with or without sleep maintenance difficulties) were randomly assigned either to intensive sleep retraining (ISR), stimulus control therapy (SCT), ISR plus SCT, or the control (sleep hygiene) treatment condition.

Intervention: ISR treatment consisted of 50 sleep onset trials over a 25-h sleep deprivation period.

Measurements and results: Treatment response was assessed with sleep diary, activity monitoring, and questionnaire measures. The active treatment groups (ISR, SCT, ISR+SCT) all resulted in significant improvements in sleep onset latency and sleep efficiency, with moderate to large effect sizes from pre- to post-treatment. Wake time after sleep onset decreased significantly in the SCT and ISR+SCT groups. Total sleep time increased significantly in the ISR and ISR+SCT treatment groups. Participants receiving ISR (ISR, ISR+SCT) experienced rapidly improved SOL and TST during treatment, suggesting an advantage of rapid improvements in sleep in response to ISR. Although there were few statistically significant differences between groups on individual variables, ISR+SCT resulted in consistently larger effect sizes of change than other treatments, including questionnaire measures of sleep quality, sleep self-efficacy, and daytime functioning. The combination treatment group (ISR+SCT) showed trends to outperform other active treatment groups with fewer treatment dropouts, and a greater proportion of treatment responders with 61% reaching "good sleeper" status. Treatment gains achieved at post-treatment in the active treatment groups were largely maintained throughout follow-up periods to 6 months.

Conclusion: This 25-hour intensive conditioning treatment for chronic insomnia can produce rapid improvements in sleep, daytime functioning, and psychological variables. Adding ISR to traditional interventions seems to result in a superior treatment response.

Keywords: Chronic insomnia; behavioral treatment; classical conditioning; intensive sleep retraining.

Figure 1

Research design and participant flow.

Figure 2

Mean sleep onset latency (SOL) and Stanford Sleepiness Scale (SSS) score by trial number during the intensive sleep retraining (ISR) treatment procedure.

Figure 3

Mean sleep diary sleep onset latencies (SOL) prior to, during, and following treatment. * Mean values are significantly different (P < 0.05) from control.

Figure 4

Mean sleep diary total sleep time (TST) prior to, during, and following treatment. *Mean values are significantly different (P < 0.05) from control, †Mean values are significantly different (P < 0.05) from SCT.

Figure 5

Mean sleep diary wake time after sleep onset (WASO) prior to, during, and following treatment. *Mean values are significantly different (P < 0.05) from control, °Mean values are significantly different (P < 0.05) from ISR.

Figure 6

Mean sleep diary sleep efficiency (SE) prior to, during and following treatment. *Mean values are significantly different (P < 0.01) from control. °Mean values are significantly different (P < 0.05) from ISR. ^†Mean values are significantly different (P < 0.05) from SCT.