Abstract
Emerging data suggest that Electro-Convulsive Treatment (ECT) may reduce depressive symptoms by increasing the expression of Brain-Derived Neurotrophic Factor (BDNF). Yet, conflicting findings have been reported. For this reason we performed a systematic review and meta-analysis of the preclinical and clinical literature on the association between ECT treatment (ECS in animals) and changes in BDNF concentrations and their effect on behavior. In addition, regional brain expression of BDNF in mouse and human brains were compared using Allen Brain Atlas. ECS, over sham, increased BDNF mRNA and protein in animal brain (effect size [Hedge’s g]: 0.38―0.54; 258 effect-size estimates, N = 4,284) but not in serum (g = 0.06, 95% CI = -0.05―0.17). In humans, plasma but not serum BDNF increased following ECT (g = 0.72 vs. g = 0.14; 23 effect sizes, n = 281). The gradient of the BDNF increment in animal brains corresponded to the gradient of the BDNF gene expression according to the Allen brain atlas. Effect-size estimates were larger following more ECT sessions in animals (r = 0.37, P < .0001) and in humans (r = 0.55; P = 0.05). There were some indications that the increase in BDNF expression was associated with behavioral changes in rodents, but not in humans. We conclude that ECS in rodents and ECT in humans increase BDNF concentrations but this is not consistently associated with changes in behavior.
Highlights
Electro Convulsive Treatment (ECT) has been used as a treatment for mood disorders for years
Our search generated 97 papers of which 23 [10,11,15,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51] fulfilled the inclusion criteria. From these we could extract 280 effect-size estimates (k) on a total of 4,670 animals on changes in Brain-Derived Neurotrophic Factor (BDNF) concentrations in animals that were subjected to ECS as compared to sham treatment or, in one case, to baseline.[31]
Our main findings are: (A) in rodents, ECS increases BDNF mRNA and protein concentration in the brain, with largest effect sizes measured in the DG, (B) the increase in BDNF is positively correlated with number of treatments and negatively with the time between the last ECT and BDNF measurement, (C) BDNF concentrations do not increase in the course of treatment in rodent and human serum, yet they increased in human plasma, and (D) the increase in BDNF following ECT is related to the number of treatment sessions but not to clinical outcome in human studies
Summary
Electro Convulsive Treatment (ECT) has been used as a treatment for mood disorders for years. Emerging data have led to the idea that ECT may reduce depressive symptoms by increasing the expression of Brain-Derived Neurotrophic Factor (BDNF), a key regulator of neuronal functioning [5]. This idea rests on the neurotrophin hypothesis, which posits that depressive disorders are secondary to a stress-induced lowered expression of BDNF [6]. Complementary, it predicts that antidepressants are efficacious, because they increase BDNF expression and boost neuronal plasticity [7,8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
