Grant et al impulse control disorders

• Gambling disorder


  Also known as pathological gambling (PG)
• Study


  • Treating gambling disorder with drugs and placebo-Grant et al. (2008)
• The study investigated factors that predict the effectiveness of opiate antagonists in the treatment of gambling disorder
• The study combined the results of two randomised control trials
• Both RCTs were double-blind, placebo-controlled experiments with independent measures
• Data gathering techniques included structured and semi-structured interviews, questionnaires and psychometric tests
• 284 american participants
• Diagnosed with pathological gambling suing DSM-IV and scored five or more on the South Oaks Gambling Screen (SOGS)
• 48% female, none pregnant or breastfeeding, all used regular contraception
• 207 outpatients from 15 psychiatric centers who participated in a 16-week trial of nalmefene (an opiate antagonist)
• The remaining 77 participated in an 18-week trial of naltrexone
• All had gambled in the past 2 weeks and gambled more than once a week
• None had used either of the trial drugs before
• Procedure


  1. Participants were randomly assigned to either the placebo group or the low, medium or higher dose in the drug group

  2. Daily doses of nalmefane doses were either 25mg, 50mg or 100mg, while naltrexone doses were 50mg 100mg or 150mg

  3. Comorbid diagnosis were identified using a structured interview and gambling behavior was investigated
• Procedure pt2

  • Severity of gambling disorder symptoms (e.g. urges and gambling behavior) was assessed before and after treatment using a modified version of the Yale-Brown Obsessive-Compulsive Scale.
  • A decrease of more than 35% was classified as a positive response to treatment.Daily functioning, anxiety and depression were assessed using questionnaires and a semi-structured interview was used to collect information about family history of psychiatric diagnoses, including alcoholism in first-degree relatives.
• Procedure pt1

  Procedure

  • Participants were randomly assigned to either the placebo group or the low, medium or higher dose in the drug group.
  • Daily doses of namefene doses were either 25mg, 50mg or 100mg, while naltrexone doses were 50mg, 100mg or 150mg.
  • Comorbid diagnosis were identified using a structured interview and gambling behavior was investigated using a questionnaire.
• Results

  • Average age of onset was 29, but there was an average of 11 years (range 1-40) between starting to gamble and being diagnosed.
  • 30% had attended Gamblers Anonymous and only 19% had previously sought professional help for their gambling
  • 48% played non-strategic games, such as slots and bingo, 16% played only strategic games, such as blackjack and poker, and 36% played both non-strategic and strategic games.
  • 24% met criteria for mood disorders, 7% for anxiety disorders, 3% for eating disorders, 42% regular tobaccousers
• Opiate antagonists


  Drugs that block the effects of opiates
• Data analysis


  1. Analysed separately

  2. Analysed together to increase sample size
• Findings


  • Similar between the two drugs
• Family history of alcoholism

  Robustly associated with positive response to treatment outcome
• Stronger baseline 'urge to gamble' scores

  Mildly associated with positive treatment response to higher doses of both drugs
• Younger participants


  More likely to respond positively to the placebo
• Participant age


  30% less effective placebo response for every ten years
• Conclusions

  • Family histories of alcoholism and, to a lesser extent, strengths of urges to gamble are associated with a positive response to opiate antagonists as a treatment for gambling disorder.