Investigating age at onset in bipolar disorder

A large body of research suggests that developing bipolar disorder at a young age is associated with a poor clinical outcome, including longer delays to treatment, greater severity of depression, and higher levels of co-occurring illnesses including anxiety and substance abuse (Agnew-Blais & Danese, 2016; Baldessarini et al., 2012; Coryell et al., 2013; Etain et al., 2012; Schurhoff et al., 2000). Despite this, no known research has investigated which factors may predict age at illness onset. Therefore, my project primarily aims to investigate if factors such as a family history of mental illness, traumatic childhood events, abuse, drug use and deprivation may be associated with bipolar disorder age at onset. The paucity of research in this area limits advances in targeted approaches to early intervention and prevention in the early stages of bipolar disorder.

It is also not clear why developing bipolar disorder at an early age may lead to worse clinical outcomes. It may be that a risk factor (e.g. childhood abuse) leads to an early age at onset during a developmentally critical period, and that this disruption to typical development results in poor long-term outcomes. Alternatively, the risk factor (e.g. childhood abuse) may be the driving force behind a poor clinical course (regardless of age at onset), whilst independently associating with age at disease onset. Consequently, my project will secondarily aim to investigate what mechanism may drive the association between an early age at onset and a poor clinical trajectory in BD. It is hoped that results from my project can help inform early intervention and prevention for bipolar disorder.