Decreased plasma brain derived neurotrophic factor levels in unmedicated bipolar patients during manic episode.
BACKGROUND
Bipolar disorder (BD) has been increasingly associated with abnormalities in neuroplasticity and cellular resilience. Brain Derived Neurotrophic Factor (BDNF) gene has been considered an important candidate marker for the development of bipolar disorder and this neurotrophin seems involved in intracellular pathways modulated by mood stabilizers. Also, previous studies demonstrated a role for BDNF in the pathophysiology and clinical presentation of mood disorders.


METHODS
We investigated whether BDNF levels are altered during mania. Sixty subjects (14 M and 46 F) were selected and included in the study. Thirty patients meeting SCID-I criteria for manic episode were age and gender matched with thirty healthy controls. Young Mania Rating Scale (YMRS) evaluated the severity of manic episode and its possible association with the neurotrophin levels.


RESULTS
Mean BDNF levels were significantly decreased in drug free/naive (224.8 +/- 76.5 pg/ml) compared to healthy controls (318.5 +/- 114.2), p < .001]. Severity of the manic episode presented a significant negatively correlation to plasma BDNF levels (r= .78; p < .001; Pearson test).


CONCLUSIONS
Overall, these results suggest that the decreased plasma BDNF levels may be directly associated with the pathophysiology and severity of manic symptoms in BD. Further studies are necessary to clarify the role of BDNF as a putative biological marker in BD.
Machado-Vieira
Rodrigo
R
Mood Disorders Program, Fundação Faculdade Federal Ciências Medicas de Porto Alegre, Bipolar Disorder Research Program, Espírita Hospital of Porto Alegre, Porto Alegre, Brazil.
Dietrich
Marcelo O
MO
Leke
Renata
R
Cereser
Vitor H
VH
Zanatto
Vanessa
V
Kapczinski
Flavio
F
Souza
Diogo O
DO
Portela
Luis V
LV
Gentil
Valentim
V
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001714:Bipolar Disorder / Q000097:blood* / Q000175:diagnosis / Q000523:psychology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012016:Reference Values; D013223:Statistics as Topic
D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor