The measurement of sleep onset latency in insomnia

Research into insomnia has relied almost exclusively upon subjects self-reports of sleep onset latency. The unreliability of self-reports have been repeatedly criticized yet despite the implementation of suggested changes substantial weaknesses remain. This study of 17 insomniacs outlines the development of a simple electrochemical device designed to yield objective estimates of sleep onset latency and compares this with independent estimates made by patients and their partners. The application of this device and the implications for the continued use of self-report measures are discussed.