Concurrent and discriminant validity of DSM-IV symptoms of impaired control over alcohol consumption in adolescents.

BACKGROUND: Little research has examined impaired control over alcohol consumption in adolescents. This study examined the concurrent and discriminant validity of two DSM-IV dependence criteria that reflect impaired control over drinking: "using more or longer than intended" (Larger/Longer) and "persistent desire or unsuccessful efforts to quit or cut down" (Quit/Cut Down).
METHODS: Adolescent drinkers, ages 13-19 (N = 173), were recruited from addictions treatment (76%) and community sources (24%). A modified SCID that included assessment of alcohol craving and questionnaires measuring dependence severity, attempts to limit drinking, and impulsivity were administered.
RESULTS: Larger/Longer had higher prevalence and an earlier onset than Quit/Cut Down, suggesting that the symptoms respectively represent milder and more severe manifestations of impaired control over drinking. Both symptoms were associated with drinking frequency, dependence severity, episodes of passing out, and an independent measure of unsuccessful attempts to limit drinking. Alcohol craving was associated with both Larger/Longer and Quit/Cut Down. Impulsivity was correlated with Larger/Longer but not Quit/Cut Down.
CONCLUSIONS: Larger/Longer and Quit/Cut Down demonstrated adequate concurrent validity. The two symptoms were distinguished by severity and differential relations with impulsivity, suggesting that Larger/Longer and Quit/Cut Down reflect different types of impaired control over alcohol consumption. Results suggest the need for improved description and scaling of the impaired control construct in adolescents.