A Randomised, Double-Blind, Placebo-Controlled Trial of As-Needed Naltrexone in the Treatment of Pathological Gambling.
OBJECTIVE
Effective treatment strategies are needed for the treatment of pathological gambling (PG). The efficacy of as-needed naltrexone was assessed in a single-centre, randomised, double-blind, placebo-controlled trial.


METHODS
The participants (n = 101) received either as-needed placebo or naltrexone (50 mg) and psychosocial support for 20 weeks. The primary outcome measure was the severity of PG assessed by the Yale-Brown Obsessive Compulsive Scale adapted for PG (PG-YBOCS). Secondary gambling-related outcome measures included thoughts/urges and behaviour subscales of PG-YBOCS as well as the highest daily expenditure and gambling frequency. In addition, RAND-36 scales of emotional well-being and social functioning were used as outcomes. The results were analysed using the intention-to-treat principle and linear random effects modelling.


RESULTS
No significant treatment group differences were found. In an exploratory analysis, emotional well-being increased in a subgroup of participants with AA genotype of opioid receptor, mu 1 (OPRM1) A118G polymorphism (p = 0.02).


CONCLUSIONS
Overall, the as-needed naltrexone may not provide substantial additional benefit for PG patients receiving psychosocial support. Replication by larger scale studies is warranted to further evaluate naltrexone administration schedules for the treatment of PG and the role of OPRM1.
Mental Health Unit, National Institute for Health and Welfare, Department of Health, Helsinki, Finland.
Leena
L
Kovanen
Syaron
S
Basnet
Sari
S
Castrén
Maiju
M
Pankakoski
Sirkku T
ST
Saarikoski
Timo
T
Partonen
Hannu
H
Alho
Tuuli
T
Lahti
D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D005260:Female; D005715:Gambling / Q000188:drug therapy* / Q000235:genetics / Q000523:psychology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009271:Naltrexone / Q000008:administration & dosage* / Q000627:therapeutic use*; D009292:Narcotic Antagonists / Q000627:therapeutic use; D020641:Polymorphism, Single Nucleotide; D011614:Psychotherapy, Brief; D017450:Receptors, Opioid, mu / Q000235:genetics; D016896:Treatment Outcome; D055815:Young Adult
D009292:Narcotic Antagonists; C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D009271:Naltrexone