title: Effects of High Frequency Repeated Transcranial Magnetic Stimulation and Continuous Theta Burst Stimulation on Gambling Reinforcement, Delay Discounting, and Stroop Interference in Men with Pathological Gambling.
abstract: Repeated transcranial magnetic stimulation (rTMS) can reduce cravings and improve cognitive function in substance dependent individuals. Whether these benefits extend to individuals with pathological gambling (PG) is unclear. High-frequency rTMS of the medial prefrontal cortex (PFC) and continuous theta burst stimulation (cTBS) of the right dorsolateral PFC can reduce impulsive choice in healthy volunteers.
  
  
  
  This study aimed to assess the effects of these two protocols on gambling reinforcement and related responses in otherwise healthy men with PG.
  
  
  
  Participants (n = 9) underwent active or sham treatments at weekly intervals in a repeated-measures, Latin square design. Subjective and physiological responses were assessed before and after a 15-min slot machine game on each session. Delay discounting and Stroop tasks measured post-game impulsive choice and attentional control.
  
  
  
  Multivariate analysis of covariance, controlling for winnings on the slot machine under each treatment, found that rTMS reduced the post-game increase in Desire to Gamble; cTBS reduced amphetamine-like effects, and decreased diastolic blood pressure. Treatment had no significant univariate effects on bet size or speed of play in the game; however, a multivariate effect for the two indices suggested that treatment decreased behavioral activation. Neither treatment reduced impulsive choice, while both treatments increased Stroop interference.
  
  
  
  rTMS and cTBS can reduce gambling reinforcement in non-comorbid men with PG. Separate processes appear to mediate gambling reinforcement and betting behavior as against delay discounting and Stroop interference. Interventions that modify risky as opposed to temporal aspects of decision making may better predict therapeutic response in PG.
authors.affiliation: Neuroscience Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada. Electronic address: martin.zack@camh.ca.
authors.forename: Martin
authors.initials: M
authors.lastname: Zack
authors.affiliation: Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Cho
authors.affiliation: Neuroscience Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Parlee
authors.affiliation: Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Jacobs
authors.affiliation: Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Crystal
authors.initials: C
authors.lastname: Li
authors.affiliation: Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Boileau
authors.affiliation: Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Antonio
authors.initials: A
authors.lastname: Strafella
mesh_terms: D000328:Adult; D065786:Delay Discounting / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005715:Gambling / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000502:physiology*; D012054:Reinforcement, Psychology; D013826:Theta Rhythm / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Delay discounting; Impulsivity; Pathological gambling; Probability discounting; TMS