Objective: The presence and specificity of a bipolar prodrome remains questioned. We aimed to characterize the prodrome prior to a first psychotic and nonpsychotic mania and to examine the phenotypic proximity to the schizophrenia prodrome.
Methods: Using a semi-structured interview, the Bipolar Prodrome Symptom Scale-Retrospective, information regarding the mania prodrome was collected from youth with a research diagnosis of bipolar I disorder and onset before 19 years of age, and/or their caregivers. Only newly emerging, at least moderately severe, symptoms were analyzed. Prodromal characteristics were compared between patients with and without subsequent psychotic mania and with published bipolar and schizophrenia prodrome data.
Results: In 52 youth (age at first mania: 13.4 +/- 3.3 years), the prodrome onset was predominantly "insidious" (>1 year, 51.9%) or "subacute" (1-12 months, 44.2%), while "acute" presentations (<1 month, 3.8%) were rare. The prodrome duration was similar in patients with (1.7 +/- 1.8 years, n = 34) and without (1.9 +/- 1.5 years, n = 18) subsequent psychotic mania (P = .70). Attenuated positive symptoms emerging late in the prodrome and increased energy/goal-directed activity were significantly more common in patients with later psychotic mania. Mania and schizophrenia prodrome characteristics overlapped considerably. However, subsyndromal unusual ideas were significantly more likely part of the schizophrenia prodrome, while obsessions/compulsions, suicidality, difficulty thinking/communicating clearly, depressed mood, decreased concentration/memory, tiredness/lack of energy, mood lability, and physical agitation were more likely part of the mania prodrome.
Conclusions: A lengthy and symptomatic prodrome makes clinical high-risk research a feasible goal for bipolar disorder. The phenotypic overlap with the schizophrenia prodrome necessitates the concurrent study of both illness prodromes.