Laboratory of Calcium Binding Proteins in the Central Nervous System, Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Post-graduate Program in Biological Sciences: Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Mol Psychiatry. 2015 Sep;20(9):1108-19. doi: 10.1038/mp.2014.117. Epub 2014 Sep 30.
It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.
有人假设精神分裂症（SZ）与脑源性神经营养因子（BDNF）的表达水平降低有关。在过去的几年中，越来越多的评估血清和血浆中 BDNF 的不同临床研究发表。现在，使用荟萃分析可以验证 BDNF 水平与 SZ 症状严重程度之间的关系，以及抗精神病药物对 BDNF 的影响。本研究旨在验证 SZ 患者外周血 BDNF 是否降低，其水平是否与阳性和阴性症状相关，以及抗精神病治疗后 BDNF 水平是否改变。本报告包括对 SZ 外周血 BDNF 的两项独立荟萃分析，共纳入 41 项研究和超过 7000 名参与者：（1）与对照组相比，SZ 患者的血清和血浆中的外周 BDNF 水平中度降低。值得注意的是，这种下降随着疾病持续时间的延长而加重。然而，外周 BDNF 水平下降的程度与阳性和阴性症状的严重程度无关。（2）在血浆中，而不是血清中，抗精神病治疗后外周 BDNF 水平持续升高，无论患者对药物的反应如何。总之，有强有力的证据表明 SZ 患者外周血 BDNF 水平降低，与先前描述的大脑 BDNF 表达降低一致。这些系统性变化是否与 SZ 的发生有关，或者它们是否仅仅是一种病理性的偶然现象，目前尚不清楚。
