Abstract
In this study, we examined the point prevalence rate of atypical features in bipolar disorder, and estimated the potential impact of these features on treatment practices in China. Using the atypical features criteria of the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM-IV), we documented the atypical symptoms in 3 906 consecutive participants with bipolar disorder enrolled at 26 psychiatric services across China. We further assessed the association between atypical features and the treatment approaches, including the prescription of antidepressants. The overall point prevalence rate of atypical features was 9.1% among patients with various bipolar disorder subtypes. When the definition was broadened to include atypical features B, the overall rate increased to 11.8%. Interestingly, among patients with the mixed state and remission subtypes, there was a significant difference in the rates of antidepressant medication usage between patients who met and those who did not meet the criteria for atypical features B. These findings indicate a trend of using antidepressants for these two types of patients with atypical features. Further, for both mixed state and remission patients, treatment approaches were related to atypical features B. Our findings provide evidence to assist clinicians to readily recognize atypical features in bipolar subtypes and can propose treatments based on these diagnoses.