Objective: The current study examined the efficacy of mailed personalized normative feedback (PNF) as a brief alcohol intervention for at-risk college drinkers, and investigated discrepancy as a possible mediator of the intervention effect.

Method: Participants consisted of 100 at-risk college drinkers who completed an alcohol-use assessment at baseline, 6-week posttest and 6-month follow-up. Measures included number of drinks consumed per heaviest drinking week, frequency of heavy-drinking episodes, peak blood alcohol concentration and number of alcohol-related problems, all for the last month. Participants were randomly assigned to either a mailed brief intervention (MBI; n = 49) or attention-control (C; n = 51) group. The MBI group received mailed PNF that was based on baseline responses to the drinking measures; the C group received a psychoeducational brochure about alcohol.

Results: Mixed-model, repeated measures ANOVAs were used to examine the effects of time, group and gender on discrepancy and the drinking variables. Following the intervention, the MBI group reported significantly higher perceived discrepancy between self and others' drinking than the C group. The MBI group reported consuming significantly fewer drinks per heaviest drinking week and engaging in heavy episodic drinking less frequently than the C group at the 6-week posttest; however, these differences were no longer evident at the 6-month follow-up. Hierarchical regression analyses did not provide evidence for the hypothesized mediating effect of discrepancy.

Conclusions: Mailed PNF may be a cost- and time-efficient means of developing discrepancy and temporarily reducing heavy alcohol consumption among at-risk college drinkers.