title: Reduced right ventrolateral prefrontal cortex activity while inhibiting positive affect is associated with improvement in hedonic capacity after 8 weeks of antidepressant treatment in major depressive disorder.
abstract: BACKGROUND
  Anhedonia, a reduced ability to experience pleasure, is a chief symptom of major depressive disorder and is related to reduced frontostriatal connectivity when attempting to upregulate positive emotion. The present study examined another facet of positive emotion regulation associated with anhedonia-namely, the downregulation of positive affect-and its relation to prefrontal cortex (PFC) activity.
  
  
  METHODS
  Neuroimaging data were collected from 27 individuals meeting criteria for major depressive disorder as they attempted to suppress positive emotion during a positive emotion regulation task. Their PFC activation pattern was compared with the PFC activation pattern exhibited by 19 healthy control subjects during the same task. Anhedonia scores were collected at three time points: at baseline (time 1), 8 weeks after time 1 (i.e., time 2), and 6 months after time 1 (i.e., time 3). Prefrontal cortex activity at time 1 was used to predict change in anhedonia over time. Analyses were conducted utilizing hierarchical linear modeling software.
  
  
  RESULTS
  Depressed individuals who could not inhibit positive emotion-evinced by reduced right ventrolateral prefrontal cortex activity during attempts to dampen their experience of positive emotion in response to positive visual stimuli-exhibited a steeper anhedonia reduction slope between baseline and 8 weeks of treatment with antidepressant medication (p < .05). Control subjects showed a similar trend between baseline and time 3.
  
  
  CONCLUSIONS
  To reduce anhedonia, it may be necessary to teach individuals how to counteract the functioning of an overactive pleasure-dampening prefrontal inhibitory system.
authors.affiliation: Center for Investigating Healthy Minds at the Waisman Center, University of Wisconsin-Madison, USA. light@wisc.edu
authors.forename: Sharee N
authors.initials: SN
authors.lastname: Light
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Heller
authors.forename: Tom
authors.initials: T
authors.lastname: Johnstone
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Kolden
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Peterson
authors.forename: Ned H
authors.initials: NH
authors.lastname: Kalin
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Davidson
mesh_terms: D000328:Adult; D059445:Anhedonia / Q000187:drug effects* / Q000502:physiology; D000928:Antidepressive Agents; D003511:Cyclohexanols / Q000627:therapeutic use; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000187:drug effects / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D011680:Pupil / Q000187:drug effects; D011795:Surveys and Questionnaires; D000069470:Venlafaxine Hydrochloride; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents; D003511:Cyclohexanols; D005473:Fluoxetine; D000069470:Venlafaxine Hydrochloride