Background: There are obstacles to early identification of bipolar disorder. Identifying and treating illness early in its time course may be associated with a better prognosis.
Methods: A questionnaire was administered at interview, when the participant was euthymic, to participants (n=240) enrolled in the Bipolar Comprehensive Outcomes Study (BCOS). Information was collected about the sequential timeline of specific symptoms of mental illness up to when they first received a diagnosis of Bipolar Disorder or Schizoaffective Disorder.
Results: Any symptoms of mental illness were first experienced at 17.5 years (median; Inter Quartile Range (IQR) 13.8-24.3; n=216) and mood swings at 18.0 years (IQR 14-25; n=197). Symptoms of depression were experienced at 18.0 years (IQR 14-25; n=197), a full episode of depression at 21.2 years (IQR 17-28.5; n=200), symptoms of mania at 21.0 years (IQR 16.8-29.5; n=212) and a full episode of mania at 24.1 years (IQR 19-30.5; n=205). Medical treatment was sought at 24.0 years (IQR 19-31.5; n=217). Participants received a diagnosis of Bipolar Disorder or Schizoaffective Disorder at 30.0 years (IQR 23-37.3; n=215). Having had a previous diagnosis other than Bipolar Disorder or Schizoaffective Disorder was reported by 120 of 216 participants who answered this question, most commonly unipolar depression (26.6%). Diagnostic delay was greater in individuals with early onset disorder.
Conclusions: Participants typically experience a long sequential course of symptoms, episodes, treatments and diagnosis. The polarity of onset is most commonly depressive, and subthreshold symptoms tend to precede threshold symptoms of both polarities.
Limitations: Data were collected retrospectively.