Clinical Expression of Bipolar Disorder Type I as a Function of Age and Polarity at Onset

Onset characteristics are associated with subsequent predominant polarity, suicidal behavior, and substance misuse in bipolar I disorder. These findings may facilitate personalized treatment strategies based on type of onset and may also facilitate early focused strategies for preventing comorbidity. Given the relatively low sensitivity and specificity of these onset characteristics for predicting clinical variables, the relevance of age and polarity at onset as specifiers in nosographical classifications will require further studies. However, polarity at onset may be the more relevant specifier, with further investigation required for age at onset.