title: Remission of depression following electroconvulsive therapy (ECT) is associated with higher levels of brain-derived neurotrophic factor (BDNF).
abstract: BACKGROUND
  Research on the association between electroconvulsive therapy (ECT) and increased brain derived neurotrophic factor (BDNF) levels has produced conflicting result. There have been few studies which have evaluated BDNF levels in clinical contexts where there was remission following treatment. The objective of this study was to investigate whether remission of depression following ECT is associated with changes in BDNF levels.
  
  
  METHODS
  Adult inpatients in a psychiatric unit were invited to participate in this naturalistic study. Diagnoses were made using the Mini-International Neuropsychiatric Interview (MINI) and symptoms were evaluated at admission and discharge using the Hamilton Rating Scale for Depression (HDRS-17). Thirty-one patients who received a diagnosis of depression and were subjected to ECT were included retrospectively. Clinical remission was defined as a score of less than eight on the HDRS-17 at discharge. Serum BDNF levels were measured in blood samples collected at admission and discharge with a commercial kit used in accordance with the manufacturer's instructions.
  
  
  RESULTS
  Subjects HDRS-17 scores improved following ECT (t = 13.29; p = 0.00). A generalized estimating equation (GEE) model revealed a remission × time interaction with BDNF levels as a dependent variable in a Wald chi-square test [Wald χ(2) = 5.98; p = 0.01]. A post hoc Bonferroni test revealed that non-remitters had lower BDNF levels at admission than remitters (p = 0.03), but there was no difference at discharge (p = 0.16).
  
  
  CONCLUSIONS
  ECT remitters had higher serum BDNF levels at admission and the level did not vary during treatment. ECT non-remitters had lower serum BDNF levels at admission, but levels increased during treatment and were similar to those of ECT remitters at discharge.
authors.affiliation: Programa de Pós-Graduacão em Ciências Médicas: Psiquiatria, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: thiagofernandovf@yahoo.com.br.
authors.forename: Thiago Fernando Vasconcelos
authors.initials: TF
authors.lastname: Freire
authors.affiliation: Programa de Pós-Graduacão em Ciências Médicas: Psiquiatria, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Psiquiatria e Medicina Legal, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Marcelo Pio de Almeida
authors.initials: MP
authors.lastname: Fleck
authors.affiliation: Programa de Pós-Graduacão em Ciências Médicas: Psiquiatria, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Psiquiatria e Medicina Legal, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Neusa Sica
authors.initials: NS
authors.lastname: da Rocha
mesh_terms: D000328:Adult; D000368:Aged; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000235:genetics; D015331:Cohort Studies; D003863:Depression / Q000097:blood / Q000209:etiology / Q000628:therapy; D004565:Electroconvulsive Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012333:RNA, Messenger / Q000378:metabolism; D012008:Recurrence; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger
keywords: BDNF; Clinical remission; Depression; ECT