title: Interrelationships among parental family history of substance misuse, delay discounting, and personal substance use.
abstract: BACKGROUND
  Despite consistent evidence of the familiality of substance misuse, the mechanisms by which family history (FH) increases the risk of addiction are not well understood. One behavioral trait that may mediate the risk for substance use and addiction is delay discounting (DD), which characterizes an individual's preferences for smaller immediate rewards compared to larger future rewards.
  
  
  OBJECTIVE
  The aim of this study is to examine the interrelationships among FH, DD, and diverse aspects of personal substance use, and to test DD as a mediator of the relationship between FH and personal substance use.
  
  
  METHODS
  The study used crowdsourcing to recruit a community sample of adults (N = 732). Family history was assessed using a brief assessment of perceived parental substance use problems, personal substance use was assessed using the Alcohol Use Disorders Identification Test and a measure of frequency of use, and delay discounting was assessed using a latent index of discounting preferences across six reward magnitudes.
  
  
  RESULTS
  Steeper discounting was significantly associated with personal alcohol, tobacco, and marijuana use, and level of substance experimentation. Steeper DD was also associated with a denser parental FH of alcohol, tobacco, and overall substance misuse. Parental FH density was significantly associated with several aspects of personal substance use, and these relationships were partially mediated by DD.
  
  
  CONCLUSIONS
  The current study suggests that impulsivity, as measured by DD, is one proximal mechanism by which parental FH increases substance use later in life. The causal role of DD in this relationship will need to be established in future longitudinal studies.
authors.affiliation: Department of Psychology, University of Georgia, Athens, GA, 30602-3013, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: VanderBroek
authors.affiliation: Department of Psychology, University of Georgia, Athens, GA, 30602-3013, USA.
authors.forename: John
authors.initials: J
authors.lastname: Acker
authors.affiliation: Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA.|Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, 60637, USA.
authors.forename: Abraham A
authors.initials: AA
authors.lastname: Palmer
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, 60637, USA.
authors.forename: Harriet
authors.initials: H
authors.lastname: de Wit
authors.affiliation: Department of Psychology, University of Georgia, Athens, GA, 30602-3013, USA. jmackill@mcmaster.ca.|Peter Boris Centre for Addictions Research, Department of Psychiatry and Behavioural Neurosciences, McMaster University/St. Joseph's Healthcare Hamilton, Hamilton, Ontario, L8N 3K7, Canada. jmackill@mcmaster.ca.
authors.forename: James
authors.initials: J
authors.lastname: MacKillop
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016241:Child of Impaired Parents / Q000523:psychology*; D065786:Delay Discounting; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007175:Impulsive Behavior; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010287:Parent-Child Relations; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D055815:Young Adult
keywords: Alcohol; Delay discounting; Family history; Impulsivity; Marijuana; Tobacco