title: Response-dependent differences in regional cerebral blood flow changes with citalopram in treatment of major depression.
abstract: Major depression (MD) is the most frequent psychiatric disorder with a predicted increase within the next decade. The understanding of the neurobiologic basis of its cause, antidepressive treatment effects, and identification of treatment outcome predictors is of crucial importance to warrant efficient medical care. The aim of our study was to investigate differences of regional cerebral blood flow (rCBF) in MD between responders and nonresponders in the beginning and differences during the course of treatment.
  
  
  METHODS
  99mTc-Labeled d,l-hexamethylpropyleneamine oxime brain scans under resting conditions were performed on 65 patients with MD. All patients were treated with citalopram as an antidepressive monotherapy. SPECT scans were performed 2 times, at the beginning (t1) and after 4 wk of medication (t2). Voxel-by-voxel analyses were performed using SPM. Unpaired t test, paired t test, and multigroup analysis were used on a significance threshold of P < 0.005 (uncorrected) to identify significant differences in rCBF between responders and nonresponders at t1, within both groups over time of treatment (t2-t1), as well as a group x time interactions.
  
  
  RESULTS
  Thirty-five patients responded after 4 wk of treatment. Distinct differences between responders and nonresponders were found at the beginning of treatment and also relating to changes in rCBF during treatment. Responders showed a higher posterior cingulate activity at t1. Furthermore, an opposite direction of rCBF changes during treatment could be observed in this area.
  
  
  CONCLUSIONS
  The differences in rCBF in responders and nonresponders in the posterior cingulate at t1 and the opposite directed changes in rCBF in both groups during treatment in this region suggest that the posterior cingulate function plays a key role in the pathophysiology of depression and may have a predictive value for antidepressive treatment outcome.
authors.affiliation: Department of Nuclear Medicine; University of Bonn, Bonn, Germany.
authors.forename: Alexius Y
authors.initials: AY
authors.lastname: Joe
authors.forename: Thomas
authors.initials: T
authors.lastname: Tielmann
authors.forename: Jan
authors.initials: J
authors.lastname: Bucerius
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Reinhardt
authors.forename: Holger
authors.initials: H
authors.lastname: Palmedo
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Maier
authors.forename: Hans-Juergen
authors.initials: HJ
authors.lastname: Biersack
authors.forename: Astrid
authors.initials: A
authors.lastname: Zobel
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000494:pharmacology; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use*; D001921:Brain / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D015283:Citalopram / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010091:Oximes; D019275:Radiopharmaceuticals; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents; D018687:Antidepressive Agents, Second-Generation; D010091:Oximes; D019275:Radiopharmaceuticals; C068296:hexamethylpropyleneamine oxime; D015283:Citalopram; D013667:Technetium