Impaired nerve growth factor homeostasis in patients with bipolar disorder

Abstract

Objective. Neuro-trophins are critically involved in neuro-plasticity, the impairment of which is a major role-player in bipolar disorder (BD), and their altered levels have been recently advocated in the patho-physiology of this affective malady. The aim of this study, therefore, was to evaluate the plasma levels of nerve growth factor (NGF) in BD patients in comparison with control subjects. Methods. Forty-nine BD type-I individuals (30 in mania and 19 in euthymia) and 36 healthy controls were assessed by Mini-plus, Young mania and Hamilton depression rating scales. NGF levels were detected by ELISA. Results. Plasma NGF concentrations were decreased in BD patients when compared to that seen with controls. BD individuals in mania had lower NGF levels than euthymic patients or controls. NGF levels were negatively correlated with the severity of mania. Conclusions. This is the first study to evaluate NGF levels in BD patients, providing further support to the hypothesis of impaired neuro-plasticity in BD. These data also suggest that NGF measurement could be used for the biological marker for manic state.

Key words::

• Biomarker
• bipolar disorder
• nerve growth factor (NGF)
• neuroplasticity
• neurotrophin

Acknowledgements

This work was funded by grants from Rede Instituto Brasileiro de Neurociência (Rede IBNet/MCT/Finep, Brazil), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil), Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig, Brazil), and by Asklepios-Med (Hungary).

Statement of interest

The authors declare that they have no conflict of interest.