Peripheral brain-derived neurotrophic factor changes along treatment with extended release quetiapine during acute mood episodes: an open-label trial in drug-free patients with bipolar disorder.

Molecules that are involved in neuronal intercommunication and adaptability of neural networks, such as brain-derived neurotrophic factor (BDNF), are targets of pathophysiological investigation in bipolar disorder (BD). Quetiapine is an attested treatment in this disorder, used in acute mood episodes. The aim of this study was to report prospective changes in serum BDNF levels in drug-free patients in acute mood episodes of BD who received treatment with extended-release quetiapine along a 16 week follow-up. Assessments were performed at baseline and weeks 2, 4, 8 and 16 with the Young Mania Rating Scale, the Hamilton Depression Rating Scale and the Clinical Global Impression severity scale. In these visits, serum BDNF levels were measured. Mixed effect models were used to investigate longitudinal changes. Twenty-five patients were included for this analysis, seventeen in a current depressive episode and eight in a manic/mixed episode. A significant improvement from baseline to endpoint was displayed. In the mixed model, significant main effects for episode and time appeared, and a time versus episode interaction showing increasing BDNF levels with time in those with a depressive episode, but a decrease in BDNF levels with time in those with a manic/mixed episode. BDNF may be a biomarker with differential response according to the polarity of mood episodes.