title: Paralimbic and lateral prefrontal encoding of reward value during intertemporal choice in attempted suicide.
abstract: BACKGROUND
  Alongside impulsive suicide attempts, clinicians encounter highly premeditated suicidal acts, particularly in older adults. We have previously found that in contrast to the more impulsive suicide attempters' inability to delay gratification, serious and highly planned suicide attempts were associated with greater willingness to wait for larger rewards. This study examined neural underpinnings of intertemporal preference in suicide attempters. We expected that impulsivity and suicide attempts, particularly poorly planned ones, would predict altered paralimbic subjective value representations. We also examined lateral prefrontal and paralimbic correlates of premeditation in suicidal behavior.
  
  
  METHODS
  A total of 48 participants aged 46-90 years underwent extensive clinical and cognitive characterization and completed the delay discounting task in the scanner: 26 individuals with major depression (13 with and 13 without history of suicide attempts) and 22 healthy controls.
  
  
  RESULTS
  More impulsive individuals displayed greater activation in the precuneus/posterior cingulate cortex (PCC) to value difference favoring the delayed option. Suicide attempts, particularly better-planned ones, were associated with deactivation of the lateral prefrontal cortex (lPFC) in response to value difference favoring the immediate option. Findings were robust to medication exposure, depression severity and possible brain damage from suicide attempts, among other confounders. Finally, in suicide attempters longer reward delays were associated with diminished parahippocampal responses.
  
  
  CONCLUSIONS
  Impulsivity was associated with an altered paralimbic (precuneus/PCC) encoding of value difference during intertemporal choice. By contrast, better-planned suicidal acts were associated with altered lPFC representations of value difference. The study provides preliminary evidence of impaired decision processes in both impulsive and premeditated suicidal behavior.
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Vanyukov
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: K
authors.initials: K
authors.lastname: Szanto
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: M N
authors.initials: MN
authors.lastname: Hallquist
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Siegle
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Reynolds
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Forman
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: H J
authors.initials: HJ
authors.lastname: Aizenstein
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA 5213,USA.
authors.forename: A Y
authors.initials: AY
authors.lastname: Dombrovski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D002755:Choice Behavior; D065786:Delay Discounting; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D059907:Functional Neuroimaging; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007175:Impulsive Behavior; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012201:Reward; D013406:Suicide, Attempted / Q000523:psychology*
keywords: Aging; discounting; impulsivity; neuroimaging; suicide