New modalities of assessment and treatment planning in depression: the sequential approach.

The sequential model of treatment for depression, i.e. the use of psychotherapy in patients who have remitted from a major depressive disorder after a course of pharmacotherapy, is an intensive two-stage approach that derives from the awareness that one course of treatment is unlikely to provide a solution to all the symptoms of patients. The aim of the sequential approach is to provide different types of treatment for as long as considered necessary in different phases of illness as determined by repeated assessments. The treatment strategies are chosen on the basis of the symptoms identified and not as predefined options. The sequential model emphasizes consideration of subclinical and residual symptomatology according to the organizing principles of macro-analysis (a relationship between co-occurring symptoms and problems is established on the basis of where treatment should commence in the first place). Diagnostic endpoints (i.e. DSM diagnoses), the customary guidance of treatment planning, are replaced by conceptualization of disorders as 'transfer stations', which are amenable to longitudinal verification and modification. The aim of this systematic review was to survey the literature concerned with the sequential approach to the treatment of depression. Randomized controlled trials were identified using MEDLINE and a manual search of the literature. In seven of the eight studies that were identified, the sequential use of pharmacotherapy and psychotherapy was found to improve long-term outcome after termination of treatment compared with clinical management and treatment as usual. Nevertheless, data on this approach are limited and more studies are necessary for detailing the various clinical steps associated with it. The sequential approach calls for a re-assessment of the design of comparative clinical trials. It allows randomization of patients who are already in treatment and assignment of them to treatment alternatives according to stages of development of their illness and not simply to disease classification. The model is thus more in line with the chronicity of mood disorders compared to the standard randomized controlled trial, which is based on the acute disease model.