One Week of Naltrexone Treatment Does Not Reduce Impulsivity During Inpatient Treatment of Alcohol-dependent Patients

Abstract

Objectives: The opioid receptor antagonist naltrexone (NTX) is widely used in alcohol dependence. The mechanism underlying NTX’s efficacy in reducing alcohol intake has yet to be determined. NTX may reduce impulsivity in alcohol-dependent patients. The current study was designed to examine the effect of NTX (50 mg/d) 7 d/wk treatment on impulsivity in NTX-treated alcoholics (NTA) compared with NTX-naive alcoholics (NNA) and healthy controls. Materials and Methods: The study included 17 NTA, 17 NNA, and 17 healthy control subjects. Impulsivity was assessed using Immediate Memory Task (IMT), The Single-Key Impulsivity Paradigm (SKIP), and Barratt Impulsiveness Scale (BIS-11). Results: NNA and NTA groups did not differ on IMT performance, SKIP performance, and BIS scores. As expected, alcohol-dependent subjects showed higher scores on the BIS and higher IMT ratios on the IMT compared with controls. SKIP performance did not differ between alcohol-dependent subjects and healthy controls. There were also significant correlations between the IMT performance and BIS scores. Conclusion: These results indicate that alcohol-dependent subjects were more impulsive, however, NTX does not seem to reduce alcohol intake by modulating impulsivity.