title: Reaching out towards cannabis: approach-bias in heavy cannabis users predicts changes in cannabis use.
abstract: OBJECTIVE
  Repeated drug exposure can lead to an approach-bias, i.e. the relatively automatically triggered tendencies to approach rather that avoid drug-related stimuli. Our main aim was to study this approach-bias in heavy cannabis users with the newly developed cannabis Approach Avoidance Task (cannabis-AAT) and to investigate the predictive relationship between an approach-bias for cannabis-related materials and levels of cannabis use, craving, and the course of cannabis use.
  
  
  METHODS
  Cross-sectional assessment and six-month follow-up in 32 heavy cannabis users and 39 non-using controls.
  
  
  METHODS
  Approach and avoidance action-tendencies towards cannabis and neutral images were assessed with the cannabis AAT. During the AAT, participants pulled or pushed a joystick in response to image orientation. To generate additional sense of approach or avoidance, pulling the joystick increased picture size while pushing decreased it. Craving was measured pre- and post-test with the multi-factorial Marijuana Craving Questionnaire (MCQ). Cannabis use frequencies and levels of dependence were measured at baseline and after a six-month follow-up.
  
  
  RESULTS
  Heavy cannabis users demonstrated an approach-bias for cannabis images, as compared to controls. The approach-bias predicted changes in cannabis use at six-month follow-up. The pre-test MCQ emotionality and expectancy factor were associated negatively with the approach-bias. No effects were found on levels of cannabis dependence.
  
  
  CONCLUSIONS
  Heavy cannabis users with a strong approach-bias for cannabis are more likely to increase their cannabis use. This approach-bias could be used as a predictor of the course of cannabis use to identify individuals at risk from increasing cannabis use.
authors.affiliation: ADAPT-lab, Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands. j.cousijn@uva.nl
authors.forename: Janna
authors.initials: J
authors.lastname: Cousijn
authors.forename: Anna E
authors.initials: AE
authors.lastname: Goudriaan
authors.forename: Reinout W
authors.initials: RW
authors.lastname: Wiers
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D001362:Avoidance Learning; D016739:Behavior, Addictive / Q000453:epidemiology / Q000523:psychology*; D003430:Cross-Sectional Studies; D003463:Cues; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018450:Disease Progression; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology*; D009042:Motivation; D009426:Netherlands; D010775:Photic Stimulation; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology; D012907:Smoking / Q000453:epidemiology / Q000523:psychology; D055815:Young Adult