Identifying effective psychological treatments for insomnia: a meta-analysis.

Insomnia is a debilitating and widespread complaint. Concern over the iatrogenic effects of pharmacological therapies has led to the development of several psychological treatments for insomnia. To clarify the effects of these treatments, 66 outcome studies representing 139 treatment groups were included in a meta-analysis. The results indicated that psychological treatments produce considerable enhancement of both sleep patterns and the subjective experience of sleep. In terms of enhancing sleep onset, active treatments were all superior to placebo therapies but did not differ greatly in efficacy. Greater therapeutic gains were available for participants who were clinically referred and who were not regular users of sedative hypnotics. Future research directions are suggested.