[Interpersonal psychotherapy from research to practice].
Interpersonal therapy (IPT) is a brief, structured psychotherapy initially intended to treat adult depression that was developed in the 1970s and manualized in 1984 by G. Klerman and his team. Two main theories served as a basis for its design: Bowlby's attachment theory and communication theory. Klerman theorized that tensions and problems in interpersonal relationships (i.e. disputes) cause psychological distress in vulnerable individuals that may lead to a major depressive episode. Clinical and epidemiological studies have shown that an insecure attachment style is strongly associated with lifetime depression. Severe depressive episodes have been correlated with avoidant attachment in women. IPT is based on the hypothesis that recent or ongoing disturbances in interpersonal relationships either trigger or follow the onset of mood disorder. In practice, IPT assists patients in analysing their interpersonal relationship modes, correlating their relational states with their mood and in learning to use better communication. Resolving difficulties in interpersonal relationships through the use of better communication skills promotes the improvement of depressive symptoms. Klerman identified four interpersonal areas that seem to be highly correlated with depressive episodes: grief (a close and important personal relation who has died), interpersonal disputes (conflicts with significant people such as a spouse or another close family member), role transition (significant life changes such as retirement, parenthood or chronic and invalidating illness) and interpersonal deficits (patients who have limited social contacts and few interpersonal relations). Classically, IPT is planned around 12-16 weekly sessions. During the initial sessions, the therapist will explore all existing interpersonal relations and any significant dysfunctions, both recent and ongoing. Following this interview, the area the patient considers as driving the current depressive episode will be designated as the focus of therapy. Evaluation of depressive symptoms by a quantitative measure (i.e. Visual Analogue Scale) and qualitative measures (activity, pleasure, quality of life) reoccurs at each session. During the intermediate sessions, therapy uses current situations and events in the designated area that particularly affect the patient's mood. Coping, communication and decision-making skills are gradually improved through a number of techniques. These include non-directive and directive exploration, clarification, encouragement of affect, and communication analysis. The therapeutic relationship is empathetic and encouraging of all progress the patient makes. The final phases close the therapy and help the patient to plan future actions and improvements. Several controlled clinical trials in adult populations have demonstrated the efficacy of IPT in treating Major Depressive Disorder (initial and recurrent episodes). It has been recommended as an appropriate treatment option in several guidelines. It can be provided in individual, couple or group formats. There remains an ongoing discussion of the efficacy of monthly maintenance sessions in recurrent depression. Since its conception, clinical trials have explored its use in specific populations such as adolescents and the elderly. IPT has also been the object of trial in other disorders such as post-partum depression, bipolar disorder, social phobia and eating disorders. This article reviews the basic principles and objectives of this therapeutic model. Theoretical concepts and results from research are also discussed. The approach is briefly described and the various therapeutic phases are discussed. Clinical trials have shown that IPT is effective in treating major depressive disorder in a wide variety of populations. Further trials are necessary to determine its efficacy in other psychiatric disorders.