Early intervention in bipolar affective disorders: Why, when and how

Bipolar disorder (BD) is a chronic and severe psychiatric disease. There are often significant delays prior to diagnosis, and only 30 to 40 % of patients will experience complete remission. Since BD occurs most often at a young age, the disorder can seriously obstruct future socio-professional development and integration. Vulnerability-stress model of BD is considered to be the result of an interaction between vulnerability genes and environmental risk factors, which leads to the onset of the disorder most often in late adolescence or early adulthood. The clinical "staging" model of BD situates the subject in a clinical continuum of varying degrees of severity (at-risk status, first episode, full-blown BD). Given the demonstrated effectiveness of early intervention in the early stages of psychotic disorder, we posit that early intervention for early stages of BD (i.e. at-risk status and first episode mania or hypomania) would reduce the duration of untreated illness and optimize the chances of therapeutic response and recovery. We conducted a narrative review of the literature to gather updated data on: (1) features of early stages: risk factors, at-risk symptoms, clinical specificities of the first manic episode; (2) early screening: targeted populations and psychometric tools; (3) early treatment: settings and therapeutic approaches for the early stages of BD. (1) Features of early stages: among genetic risk factors, we highlighted the diagnosis of BD in relatives and affective temperament including as cyclothymic, depressive, anxious and dysphoric. Regarding prenatal environmental risk, we identified peripartum factors such as maternal stress, smoking and viral infections, prematurity and cesarean delivery. Later in the neurodevelopmental course, stressful events and child psychiatric disorders are recognized as increasing the risk of developing BD in adolescence. At-risk symptoms could be classified as "distal" with early but aspecific expressions including anxiety, depression, sleep disturbance, decreased cognitive performance, and more specific "proximal" symptoms which correspond to subsyndromic hypomanic symptoms that increase in intensity as the first episode of BD approaches. Specific clinical expressions have been described to assess the risk of BD in individuals with depression. Irritability, mixed and psychotic features are often observed in the first manic episode. (2) Early screening: some individuals with higher risk need special attention