Social context and impaired control over alcohol use during naturally occurring drinking episodes.

RATIONALE: Drinking more than intended is a core feature of impaired control over alcohol use, yet scant research has sought to understand the dynamic manifestation, and event-level correlates, of exceeding intended intoxication, a related construct. This study hypothesized that contextual influences – number of drinking peers and perceived peer intoxication – would predict exceeding intended intoxication in real-time and quantity of alcohol consumed after intended intoxication was met.

METHODS

Young adults reporting high intensity drinking (N = 199) completed 28-days of ecological momentary assessments, including morning/evening reports and real-time reports at drink initiation and every 45 min thereafter until done drinking. Multilevel models tested whether contextual influences predicted exceeding intended levels of intoxication during real-time reports (yes/no) and drinking quantity after intended intoxication was met.

RESULTS

Being around at least one person perceived to be intoxicated within a given moment and the proportion of these moments across a given drinking day predicted exceeding intended intoxication levels within participants. In contrast, being around a higher-than-average number of drinking peers during the real-time report when intended intoxication was met predicted within-person increases in quantity of consumption thereafter on a given drinking day. Findings were unchanged when accounting for drinking quantity consumed prior to a given real-time report.

CONCLUSIONS

Distinct contextual influences predicted different operationalizations of real-time impaired control over alcohol use. Adaptive interventions may seek to mark high-risk episodes based upon context, provide feedback regarding intended versus real-time intoxication, and motivate use of protective strategies to reduce impaired control during drinking events.