title: Neural responses to happy facial expressions in major depression following antidepressant treatment.
abstract: OBJECTIVE
  Processing affective facial expressions is an important component of interpersonal relationships. However, depressed patients show impairments in this system. The present study investigated the neural correlates of implicit processing of happy facial expressions in depression and identified regions affected by antidepressant therapy.
  
  
  METHODS
  Two groups of subjects participated in a prospective study with functional magnetic resonance imaging (fMRI). The patients were 19 medication-free subjects (mean age, 43.2 years) with major depression, acute depressive episode, unipolar subtype. The comparison group contained 19 matched healthy volunteers (mean age, 42.8 years). Both groups underwent fMRI scans at baseline (week 0) and at 8 weeks. Following the baseline scan, the patients received treatment with fluoxetine, 20 mg daily. The fMRI task was implicit affect recognition with standard facial stimuli morphed to display varying intensities of happiness. The fMRI data were analyzed to estimate the average activation (overall capacity) and differential response to variable intensity (dynamic range) in brain systems involved in processing facial affect.
  
  
  RESULTS
  An attenuated dynamic range of response in limbic-subcortical and extrastriate visual regions was evident in the depressed patients, relative to the comparison subjects. The attenuated extrastriate cortical activation at baseline was increased following antidepressant treatment, and symptomatic improvement was associated with greater overall capacity in the hippocampal and extrastriate regions.
  
  
  CONCLUSIONS
  Impairments in the neural processing of happy facial expressions in depression were evident in the core regions of affective facial processing, which were reversed following treatment. These data complement the neural effects observed with negative affective stimuli.
authors.affiliation: Institute of Psychiatry, King's College London, 103 Denmark Hill, London SE5 8AF, UK. c.fu@iop.kcl.ac.uk
authors.forename: Cynthia H Y
authors.initials: CH
authors.lastname: Fu
authors.forename: Steve C R
authors.initials: SC
authors.lastname: Williams
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Brammer
authors.forename: John
authors.initials: J
authors.lastname: Suckling
authors.forename: Jieun
authors.initials: J
authors.lastname: Kim
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Cleare
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Walsh
authors.forename: Martina T
authors.initials: MT
authors.lastname: Mitterschiffthaler
authors.forename: Chris M
authors.initials: CM
authors.lastname: Andrew
authors.forename: Emilio Merlo
authors.initials: EM
authors.lastname: Pich
authors.forename: Edward T
authors.initials: ET
authors.lastname: Bullmore
mesh_terms: D000928:Antidepressive Agents / Q000627:therapeutic use*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy* / Q000523:psychology; D005149:Facial Expression; D005473:Fluoxetine / Q000627:therapeutic use; D007839:Functional Laterality / Q000502:physiology; D006240:Happiness; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D012938:Social Perception; D014796:Visual Perception / Q000502:physiology*
chemical_list: D000928:Antidepressive Agents; D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors