[Sleep induction].

Physiological sleep induction is a fragile phenomenon which may be altered by environmental factors and various somatic and psychiatric disorders. Therefore sleep induction disorder is a common component of different types of insomnia, including sleep-onset insomnia and to a lesser degree multiple awakenings insomnia and early morning awakening insomnia. The treatment of sleep induction disorders is difficult and requires a precise analysis of the disorder and its aetiological factors. Specific treatment of aetiological factors is more likely to be efficacious in the long term than pharmacological sleep induction (eg: psychiatric disorders, sleep apnea syndrome, restless leg syndrome, periodic movements in sleep, disorders of the sleep-wake schedule...) when the use of hypnotic drugs is necessary agents not altering sleep architecture are preferred. Non-pharmacological methods could be used to induce sleep because they provide a better long term efficacy: sleep hygiene, relaxation techniques, biofeedback technique, psychotherapeutic techniques. Recently, some authors stress the use of treatment by restriction of time in bed and stimulus control treatment.