A matter of perspective: The convergent and incremental validity of informant-reported drinking motives

Introduction: Drinkers have social and affective reasons for using alcohol (‘drinking motives’). Historically, drinking motives are self-reported. Informant-reports of drinking motives may be useful in corroborating self-report data. Thus, we investigated the correspondence between self- and informant-reports of drinking motives and the incremental validity of informant-reported motives in predicting targets' future alcohol problems. Methods: Measures were completed by 174 university-aged, same-sex drinking buddy dyads (66% women) across two waves separated by 30 days. Dyad members who contacted study organisers were treated as targets, and their buddies as informants. Targets self-reported their own drinking motives at baseline, as well as their own alcohol problems at baseline and 30 days later. Informants reported on targets' drinking motives at baseline. Results: Self- and informant-reports of targets' internal drinking motives (coping-depression and enhancement) showed significant, small positive correlations. Informants-reports of these same internal drinking motives (as well as coping-anxiety) predicted change in targets' alcohol problems over time, thereby providing additional predictive validity beyond that provided by targets' self-reports. Discussion and Conclusions: We encourage incorporating informant-reported internal drinking motives when assessing risk for escalating problem drinking in emerging adult drinkers.