Insomniacs' reported use of CBT components and relationship to long-term clinical outcome.
Harvey L., Inglis SJ., Espie CA.
Although there is considerable evidence for the efficacy of non-pharmacological treatment of insomnia, many of the larger trials have delivered CBT in multicomponent format. This makes it impossible to identify critical ingredients responsible for improvement. Furthermore, compliance with home implementation is difficult to ascertain in psychological therapies, and even more so when trying to differentiate across a range of elements. In the present report, 90 patients who had completed 12 month follow-up after participation in a clinical effectiveness study of CBT in general medical practice, responded to a questionnaire asking them about their use of the ten components of the programme. Reports of home use were then entered as predictors of clinical response to treatment. Results indicated that reported home use of stimulus control/sleep restriction was the best predictor of clinical improvement in sleep latency and nighttime wakefulness. Cognitive restructuring also contributed significantly to reduction in wakefulness. In spite of being the most highly endorsed component (by 79% of respondents) use of relaxation did not predict improvement on any variable. Similarly, sleep hygiene was unrelated to sleep pattern change and use of imagery training was modestly predictive of poor response in terms of sleep latency. There are methodological limitations to this type of post hoc analysis, nevertheless, these results being derived from a large patient outcome series raise important issues both for research and clinical practice.