Some people with major depressive disorder (MDD) may be at a pre-onset stage for bipolar disorder (BD), where early identification or prevention efforts may be feasible. We aimed to identify rates and characteristics predictive of transition to BD in prospective follow-up studies of people with MDD. Login using your SSSFT NHS OpenAthens for full text. SSOTP - You can request a copy of this article by replying to this email. Please ensure you are clear which article you are requesting.