BACKGROUND: The Bipolar Disorder Patients Follow-up (BDPF) project is a longitudinal, prospective and naturalistic study. The purpose of the present report is to introduce the project, elaborate its methods, and present the reliability data of the utilized symptoms rating scales. METHODS: The sampling started in May 2008 and is still in progress. The probands are assessed at the beginning of the sampling and then 2 and 6 months later and then every 6 months using several instruments to identify psychiatric comorbidities, symptoms severity, quality of life, attempted suicide rate, treatment compliance, and some other factors. RESULTS: The results could lead to increase the clinicians' awareness about the clinical picture of this disorder in ...