[Prodromal phase in bipolar disorder]

The prodromal phase is generally described as a subsyndromal stage preceding the disease onset. The characterization of such phase found its main purpose in secondary prevention. Up to now, clinical research relating to this topic in mental health has primarily focus on schizophrenic disorders. Over the last years, some studies have applied similar methods in order to characterize a preclinical phase in bipolar disorders. In spite of the fact that this strategy appears less adequate in bipolar disorders, these studies have demonstrated the existence of prodromal signs in a majority of patients. However, these features appear for the moment neither sufficiently characteristic, nor sufficiently specific to allow the construction of suitable assessment instruments, or to suggest precise guidelines in the management of these subjects. Also, these prodromal features show considerable overlap with other psychiatric disorders, especially attention-deficit hyperactivity disorder (ADHD) and schizophrenia Interestingly, a limited number of studies have looked at the number of patients considered in a prodromal phase of schizophrenia which later developed a bipolar disorder and reported substantial proportions of subjects in this case, further highlighting the obvious bias in favor of schizophrenia in the actual prevention politics. In order to identify potential candidates at a prodromal phase of bipolar disorders that could benefit from early intervention, studies have relied on both high genetic risk and symptoms at the boundary of the actual classification. However, even within such approach, pharmacological treatments have not proven obvious advantage in terms of prevention. It is suggested that adopting a more longitudinal vision of the disease and, given the mean age of onset of bipolar disorder and a fortiori of its prodromal phase, a more developmental perspective of individuals, could help lowering the confusion in this field ; Also, given the considerable overlap in prodromal features between different psychiatric disorders, early detection programs could benefit from implementing approach open to multiple diseases assessment, rather than hyper-specialization in a specific disorder.