title: Regional brain volumes, diffusivity, and metabolite changes after electroconvulsive therapy for severe depression.
abstract: OBJECTIVE
  To investigate the role of hippocampal plasticity in the antidepressant effect of electroconvulsive therapy (ECT).
  
  
  METHODS
  We used magnetic resonance (MR) imaging including diffusion tensor imaging (DTI) and proton MR spectroscopy (1H-MRS) to investigate hippocampal volume, diffusivity, and metabolite changes in 19 patients receiving ECT for severe depression. Other regions of interest included the amygdala, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex, and hypothalamus. Patients received a 3T MR scan before ECT (TP1), 1 week (TP2), and 4 weeks (TP3) after ECT.
  
  
  RESULTS
  Hippocampal and amygdala volume increased significantly at TP2 and continued to be increased at TP3. DLPFC exhibited a transient volume reduction at TP2. DTI revealed a reduced anisotropy and diffusivity of the hippocampus at TP2. We found no significant post-ECT changes in brain metabolite concentrations, and we were unable to identify a spectral signature at ≈1.30 ppm previously suggested to reflect neurogenesis induced by ECT. None of the brain imaging measures correlated to the clinical response.
  
  
  CONCLUSIONS
  Our findings show that ECT causes a remodeling of brain structures involved in affective regulation, but due to their lack of correlation with the antidepressant effect, this remodeling does not appear to be directly underlying the antidepressant action of ECT.
authors.affiliation: Psychiatric Centre Copenhagen (Rigshospitalet), Denmark.|Department of Neuroscience and Pharmacology, Laboratory of Neuropsychiatry, University of Copenhagen, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Jorgensen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Magnusson
authors.affiliation: Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.|Biomedical Engineering, DTU Elektro, Technical University of Denmark, Lyngby, Denmark.
authors.forename: L G
authors.initials: LG
authors.lastname: Hanson
authors.affiliation: Psychiatric Centre Copenhagen (Rigshospitalet), Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Kirkegaard
authors.affiliation: Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY, USA.|Department of Radiology, Stony Brook Medicine, Stony Brook, NY, USA.
authors.forename: H
authors.initials: H
authors.lastname: Benveniste
authors.affiliation: Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY, USA.|Department of Radiology, Stony Brook Medicine, Stony Brook, NY, USA.
authors.forename: H
authors.initials: H
authors.lastname: Lee
authors.affiliation: Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Svarer
authors.affiliation: Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark.
authors.forename: J D
authors.initials: JD
authors.lastname: Mikkelsen
authors.affiliation: Psychiatric Centre Copenhagen (Rigshospitalet), Denmark.|Department of Neuroscience and Pharmacology, Laboratory of Neuropsychiatry, University of Copenhagen, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Fink-Jensen
authors.affiliation: Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark.
authors.forename: G M
authors.initials: GM
authors.lastname: Knudsen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.|Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark.
authors.forename: O B
authors.initials: OB
authors.lastname: Paulson
authors.affiliation: Psychiatric Centre Copenhagen (Rigshospitalet), Denmark.
authors.forename: T G
authors.initials: TG
authors.lastname: Bolwig
authors.affiliation: Psychiatric Centre Copenhagen (Rigshospitalet), Denmark.|Department of Neuroscience and Pharmacology, Laboratory of Neuropsychiatry, University of Copenhagen, Copenhagen, Denmark.
authors.forename: M B
authors.initials: MB
authors.lastname: Jorgensen
keywords: depression; diffusion tensor imaging; electroconvulsive therapy; hippocampus; magnetic resonance imaging; magnetic resonance spectroscopy