Alcohol-induced place conditioning in moderate social drinkers.

AIMS

To test whether non-dependent drinkers show place preference for a location paired with alcohol, and to test if the amount of time spent in the alcohol-paired location is related to self-reported subjective alcohol effects experienced in that environment.

DESIGN

Two groups of subjects completed six conditioning sessions: three with alcohol (0.8 g/kg) and three without alcohol. Individuals were assigned randomly to two groups, paired and unpaired, in a 2 : 1 ratio. The paired group (n = 78) received alcohol in one testing room and no-alcohol in another testing room (biased assignment). The unpaired group (n = 30) received alcohol and no-alcohol in each testing room.

SETTING

Human Behavioral Pharmacology Laboratory, University of Chicago, Chicago, IL, USA (single site).

PARTICIPANTS

Healthy male and female social drinkers (n = 108) aged 21-40 years participated in the study (consisting of 10 separate laboratory visits) between March 2012 and August 2014 (an average of 36 separate subject visits per month).

MEASUREMENTS

The primary outcome measure was the pre- to post-conditioning change in the percentage of time spent in the least preferred room (obtained during drug-free exploration tests conducted at separate visits before and after the six conditioning sessions were completed). Secondary measures included self-reported subjective mood and drug effects obtained during the conditioning sessions.

FINDINGS

The groups differed in the change in the percentage of time spent in the initially least preferred room, from pre- to post-conditioning; paired group = 11.0%, unpaired group = -1.4%, mean difference = 12.4%, 95% confidence interval = 1.9-23.0, P = 0.02. The change in the percentage of time spent in the least-preferred room was related to the self-reported sedative effects of alcohol during conditioning sessions among paired group participants only.

CONCLUSIONS

Non-dependent consumers of alcohol appear to develop a behavioral preference for locations paired with alcohol consumption, more so for those who experience sedative effects from alcohol in those locations.