Overestimations of hypnotic drug effects by insomniacs—a hypothesis

Data on subjective estimates and polygraphic measures of total sleep time and sleep latency were collected from the literature and analyzed for accordance or discrepancy between subjective and objective (EEG-based) mean values in experiments on acute treatment of insomnia by benzodiazepine hypnotics. In baseline placebo conditions there was a tendency to overestimate the disturbance of sleep. After drug administration, sleeping was overestimated. Within both subjective and objective measures, the magnitude of drug effects was correlated with poor initial sleep. If discrepancies between subjective and objective measures per se were analyzed, a number of correlational factors led to the hypothesis that psychological characteristics of a given population play a primary role: populations overestimating their sleep disturbances also tended to overestimate hypnotic drug effects. However, overestimations of drug effects were not correlated with type of drug or objective measures of sleep disturbance before treatment.