Comparison of categorical alcohol dependence versus a dimensional measure for predicting weekly alcohol use in heavy drinkers.
BACKGROUND
The DSM specifies categorical criteria for psychiatric disorders. In contrast, a dimensional approach considers variability in symptom severity and can significantly improve statistical power. The current study tested whether a categorical, DSM-defined diagnosis of Alcohol Dependence (AD) was a better fit than a dimensional dependence measure for predicting change in alcohol consumption among heavy drinkers following a brief alcohol intervention (BI). DSM-IV and DSM-5 alcohol use disorder (AUD) measures were also evaluated.


METHODS
Participants (N=246) underwent a diagnostic interview after receiving a BI, then reported daily alcohol consumption using an Interactive Voice Response system. Dimensional AD was calculated by summing the dependence criteria (mean=4.0; SD=1.8). The dimensional AUD measure was a summation of positive Alcohol Abuse plus AD criteria (mean=5.8; SD=2.5). A multi-model inference technique was used to determine whether the DSM-IV categorical diagnosis or dimensional approach would provide a more accurate prediction of first week consumption and change in weekly alcohol consumption following a BI.


RESULTS
The Akaike information criterion (AIC) for the dimensional AD model (AIC=7625.09) was 3.42 points lower than the categorical model (AIC=7628.51) and weight of evidence calculations indicated there was 85% likelihood that the dimensional model was the better approximating model. Dimensional AUD models fit similarly to the dimensional AD model. All AUD models significantly predicted change in alcohol consumption (p's=.05).


CONCLUSIONS
A dimensional AUD diagnosis was superior for detecting treatment effects that were not apparent with categorical and dimensional AD models.
Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05401, USA; Department of Psychiatry, University of Vermont, 1 South Prospect Street, Burlington, VT 05401, USA. Electronic address: tfazzino@uvm.edu.
Tera L
TL
Fazzino
Department of Psychiatry, University of Vermont, 1 South Prospect Street, Burlington, VT 05401, USA.
Gail L
GL
Rose
Department of Psychology, University of Vermont, 2 Colchester Avenue, Burlington, VT 05401, USA.
Keith B
KB
Burt
Department of Psychiatry, University of Vermont, 1 South Prospect Street, Burlington, VT 05401, USA.
John E
JE
Helzer
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology / Q000523:psychology*; D019973:Alcohol-Related Disorders / Q000453:epidemiology / Q000523:psychology*; D000437:Alcoholism / Q000453:epidemiology / Q000523:psychology*; D003627:Data Interpretation, Statistical; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011237:Predictive Value of Tests; D016896:Treatment Outcome; D055815:Young Adult
Alcohol use disorder; DSM-5; DSM-IV; Diagnosis; Dimensional; Multi-model inference