Résumé
The study of the interconnection between the quality of sleep and the depressive episode requires a pathway and good reasoning in order to be able to establish a certain link or not. Sleep must be defined, its structure studied, its role explained and its disorders discussed.Depression can only be understood if it is determined, from its symptoms to its treatment. We decided to study obstructive sleep apnoea syndrome (OSAS) because it is one of the most common sleep disorders in the population. The prevalence of depression in people with this condition is significant enough to demonstrate an interdependence.Once the link had been established, it seemed interesting to study the treatment of the depressive episode by means of action on sleep. We therefore chose to mention two methods, little used until now, which seemed to us to present a relevant approach but also different from those usually used. The impact of a disturbed sleep/wake rhythm on the occurrence of a depressive episode is real and we therefore tried to re-establish a regulated cycle likely to lead to an improvement in the symptoms of depression.Melatonin, used as a complement in the treatment of insomnia, seemed to us to be a little exploited possibility in the treatment of depression. The results showed that some patients responded favourably to this molecule and its analogues, thus allowing us, once again, to confirm the real existence of the link between sleep and the depressive episode.