Insomnia: II. Assessment and treatment of chronic insomnia.

Evidence for non-pharmacological effects of hypnotics on sleep is presented. This suggests that behavioural variables may be involved in the regulation of sleep onset in insomnia. Chronic 'true' insomnia is described in terms of precipitating events: fixed behavioural patterns which perpetuate it and the disordered timing of electrophysiological and hormonal events. Specific behavioural factors relevant to an individual patient's insomnia must be identified. The factors are: (i) the patient's expectations of the experience of going to sleep and his/her belief that he can or cannot control the onset of sleep, (ii) the patients' personal theory of the cause of the problem, (iii) what the patient says to himself privately about the problem, (iv) the presence of stimuli in the sleep setting which arouse the patients including objects, persons and behavioural rituals. Treatment requires that patients be taught special skills, individually tailored to the specific behavioural variables found to perpetuate their insomnia. Non specific 'placebo' effects are also involved as is the case with drug administration. Patients who fail to respond to treatment may have a masked disturbance of circadian rhythms. This recent observation requires the addition of new approaches to assessment and treatment.