To identify some of the main features of bipolar disorder for both first-episode (FE) mania and the preceding prodromal phase, in order to increase earlier recognition.

One thousand and ninety manic patients (FE=81, multiple-episodes [ME]=1009) were assessed for clinical and temperamental characteristics.

Compared to ME, FE patients reported more psychotic and less depressive symptoms but were comparable with respect to temperamental measures and comorbid anxiety. The following independent variables were associated with FE mania: a shorter delay before correct diagnosis, greater substance use, being not divorced, greater stressors before current mania, a prior diagnosis of an anxiety disorder, lower levels of depression during index manic episode, and more suicide attempts in the past year.

In FE patients, the diagnosis of mania may be overlooked, as they present with more psychotic symptoms than ME patients. The prodromal phase is characterised by high levels of stress, suicide attempts, anxiety disorders and alcohol or substance abuse. Data suggest to consider these prodromes as harmful consequences of temperamental predispositions to bipolar disorder that may concur to precipitate mania onset. Their occurrence should therefore incite clinicians to screen for the presence of such predispositions, in order to identify patients at risk of FE mania.