Objective: There are several studies which suggest that mental health outcomes are improved if illness is diagnosed promptly and accurately and the correct treatment is commenced early in the course of illness. Unfortunately, many patients experience many years of chronic mental illness prior to receiving an appropriate evidence based therapy. This delay in diagnosis and consequent delay in best treatment may contribute towards a deteriorating illness course, worsening prognosis and poor treatment outcomes. Participants in the in the Bipolar Comprehensive Outcomes Study (BCOS) were asked about their history of illness prior to their participation in BCOS in order to investigate diagnostic delay. BCOS is a 2-year observational study of people with Bipolar Disorder or Schizoaffective Disorder (N=239).

Methods: A questionnaire was administered to BCOS participants when euthymic. Retrospective 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: There was a mean delay of 12.5 years between first experiencing any symptoms of mental illness and receiving a diagnosis of Bipolar Disorder or Schizoaffective Disorder for BCOS participants. Diagnostic delay was greater in individuals with early onset disorder. Many participants reported having previously being diagnosed and treated for unipolar depression.

Conclusions: Participants typically experience a long sequential course of symptoms, episodes, treatments and alternative diagnoses prior to receiving a diagnosis of Bipolar Disorder or Schizoaffective Disorder.