P-179 - Brain-derived neurotrophic factor as a biomarker of clinical response in bipolar disorder: 16 week follow-up study

Despite therapeutic advances, we still have difficulties in predicting response to treatment in bipolar disorder (BD). Brain-Derived Neurotrophic Factor (BDNF) has been put forward as a potential peripheral marker of treatment response. To prospectively study the relation between clinical response to treatment and serum BDNF levels. To investigate a) a possible association between serum BDNF levels and clinical response along 16 week follow-up and b) the role of val66met polymorphism in clinical response in a sample of drug-free patients with BD going through a mood episode. This is a naturalistic, open-label prospective nested case control study matched for age, gender and ethnicity. Patients were 18 years or older, required BD diagnosis, undergoing a current manic, mixed or depressive episode and be off-medication for at least 2 weeks. Clinical assessment and blood withdrawn were conducted along follow-up. At the end of the study, patients were classified according to clinical response. 25 of 36 (69.4%) of the patients were female and the mean age was 37.8 (SD 11.8) years old. Baseline serum BDNF levels did not show any difference between patients and controls (p = 0.075).There was a significant negative correlation between differences in serum BDNF levels and in CGI score along follow-up (r = −.372, p = 0.028). Serum BDNF levels were significant higher in responders compared to non-responders at week 4, 8 and 16 (p = 0.026, p = 0.009, p = 0.001 respectively). Val66met polymorphism did not seem to interfere in clinical response. Changes in serum BDNF levels may help in monitoring treatment response.