Abstract
Insomnia is a condition characterized by subjective complaints of insufficient sleep and poor daytime functioning. Objective measures of sleep and daytime functioning, however, seldom show evidence of a similar degree of dysfunction. Most insomniacs, for example, do not suffer from sleep deprivation or daytime sleepiness. This discrepancy between subjective and objective measures of sleep and daytime functioning suggests that cognitive factors may play a central role in persistent insomnia. In particular, it is argued that fears about insufficient sleep and its adverse daytime consequences tend to interfere with sleep, thereby causing a vicious cycle which serves to maintain the insomnia. It is also argued that perfectionist standards and other dysfunctional beliefs may predispose people to these kinds of fears. Finally, existing models for cognitive-behavioural treatment of insomnia are criticized for being almost exclusively focused on the night-time aspects of insomnia. If insomnia is maintained by various kinds of vicious cycles involving fears, beliefs, and standards with regard to daytime functioning, these daytime aspects of insomnia should receive more attention in cognitive-behavioural treatment.