L'observance thérapeutique dans les troubles dépressifs récurrents est difficile à obtenir. Cette pathologie constitue d'une part un trouble psychiatrique, d'autre part un trouble dépressif, enfin un trouble chronique : chacune de ces caractéristiques est un obstacle à une observance satisfaisante. Diverses interventions sont susceptibles d'améliorer l'observance chez les patients dépressifs. L'information du patient, largement encouragée aujourd'hui aussi bien par les médecins que par le législateur, doit être aussi complète que possible ; elle doit porter sur les facteurs qui favorisent la dépression, et sur la logique des stratégies thérapeutiques proposées. Par ailleurs, le maintien, grâce à un traitement adapté, d'une euthymie, est probablement le meilleur garant de l'observance. La poursuite d'un traitement antidépresseur au long cours ou la mise en place d'un thymorégulateur (valproate surtout) ont, dans les deux cas, fait la preuve de leur efficacité, avec une supériorité significative par rapport au placebo. Les enjeux d'une bonne observance thérapeutique sont majeurs : le traitement est en effet capable de diminuer le risque de récurrences dépressives : il permet probablement d'atténuer également la vulnérabilité ultérieure à la dépression, même après interruption du traitement, comme le souligne la théorie du kindling de R. Post.

It is difficult to achieve treatment compliance in recurrent depressive disorders. This disease involves a combination of psychiatric and depressive disorders and is a chronic condition : all of the characteristic features of the disease constitute an obstacle to compliance. Compliance in depressive patients may be improved through various approaches. Information provided to patients, which is widely encouraged today both by doctors and by the regulatory authorities, must be as complete as possible ; it must include discussion of factors of that favor depression, as well as the logical basis of the management approach proposed. Furthermore, the best guarantee of compliance is probably maintenance of euthymia by means of suitable treatment. Long-term therapy with antidepressants and the institution of a mood regulator (valproate in particular) have both been shown to be efficacious and significantly superior to placebo. Published studies show that continued treatment with an antidepressant can reduce the risk of depressive relapse noted during long-term follow-up (between 18 months and 5 years) by at least 50%. This has been demonstrated for both tricyclic antidepressants and specific serotonin reuptake inhibitors. The need for continued long-term administration of the dosages with proven efficacy during the acute episode has been demonstrated for imipramine but also appears to have been verified for SSRIs. Even when depressive relapse occurs, it is often less severe if the antidepressant treatment has been continued. Although first-line preventive therapy generally comprises long-term continued administration of the antidepressant, use of mood regulators may occasionally be proposed : valproic acid is generally prefered over lithium assaults on the ground of safety. However, there are few studies demonstrating the preventive efficacy of structured psychotherapy against recurrence of depression. Good treatment compliance entails major benefits : the prescribed treatment is able to reduce the risk of recurrence of depression, and in all probability also reduces subsequent vulnerability to depression, even after treatment discontinuation, as emphasized by the kindling theory of R. Post.