Decreased plasma neurotrophin-4/5 levels in bipolar disorder patients in mania

Izabela G Barbosa, Isabela B Morato, Rodrigo B Huguet, Fabio L Rocha, Rodrigo Machado-Vieira, Antônio L Teixeira

Objective: To evaluate two poorly explored neurotrophins (NT), NT-3 and NT-4/5, in bipolar disorder (BD). Methods: Forty patients with type I BD (18 in remission and 22 in mania) and 25 healthy controls matched for age, gender, and educational attainment were enrolled in this study. All subjects were assessed by the Mini-International Neuropsychiatric Interview; the Young Mania Rating Scale and the Hamilton Depression Rating Scale were used to evaluate severity of symptoms in BD patients. Plasma levels of NT-3 and NT-4/5 were measured by enzyme-linked immunosorbent assay (ELISA). Results: BD patients in mania presented decreased NT-4/5 plasma levels in comparison with controls (p < 0.05). There were no significant differences in NT-3 plasma levels between BD patients and controls. Conclusion: These findings corroborate the view that neurotrophin dysfunction is associated with mood states in patients with BD.