[Bipolarity: from manic-depressive disease to bipolar disorder].

Until recently, bipolar disorder was viewed as a relatively rare condition characterized by periods of euphoric excitement and depressive retardation which was easy to diagnose, and easy to treat thanks with lithium and new prophylactic treatments. In fact, bipolar disorder encompasses a variety of conditions, whose overall lifetime prevalence in the general population may be between 5 and 8%. Long term with lithium and other compounds are very effective but must be combined with non pharmacological therapies. Over the past two decades, advances in genetic, brain imagings, and biochemical have improved our knowledge on the pathophysiological mechanisms underlying these disorders.