Individuals with alcohol use disorders (AUDs) vary widely in their age of onset of use, patterns of drinking, and symptom profiles. AUDs are often 'divided' into two categories: alcohol abuse (AA) and alcohol dependence (AD), with AA perceived as a milder syndrome that might develop into AD over time. A recent study of the clinical features of AUDs, with a focus on family liability, has found that – contrary to expectations – AA symptoms better reflect familial risk for AUDs than AD symptoms.
Results will be published in the December 2012 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"We decided to look at the clinical features of AA and AD as they correspond to familial liability to AUDs because familial risk of illness has been long used as a major validator of diagnostic approaches in psychiatry," explained Kenneth S. Kendler, professor of psychiatry at the Virginia Commonwealth University School of Medicine and corresponding author for the study. "For example, in the Diagnostic and Statistical Manual of Mental Disorders-III (DSM-III) criteria, it was assumed the AA and AD represent distinct syndromes. Since then, results have accumulated to suggest that these two categories are very highly correlated and may in fact jointly represent one underlying dimension of risk.
The researchers examined clinical features of AUDs among 1,120 twins from the Virginia Twin Study of Psychiatric and Substance Use Disorders who met Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria for lifetime AUDs. Analysis focused on whether clinical features of AUDs, including individual DSM-IV criteria for AD and AA, predicted risk for AUDs in cotwins and/or parents.
Results indicate that individual DSM-IV criteria for AA and AD differ meaningfully in the degree to which they reflect the individual's familial/genetic liability to AUDs. Importantly, and contrary to expectations, the familial/genetic risk to AUDs was better reflected by symptoms of alcohol abuse and negative psychosocial consequences of AUDs than by early age at onset of drinking, or symptoms of tolerance and withdrawal.
"Symptoms of alcohol abuse do a better job of reflecting the familial risk for AUDs than symptoms of dependence," said Kendler. "This is not what we expected. Clearly the symptoms of alcohol abuse may have more validity than they are commonly given credit for."
The most consistent single predictor of familial risk was AUD-associated legal problems, the researchers noted, one of the negative psychosocial consequences of AUDs, which is the one criterion slated for removal in the impending DSM-5.
"This removal is slated to occur largely through the influence of the International Classification of Diseases 11th Revision (ICD-11) which is used worldwide and is itself slated for revision by 2015," explained Kendler. "The DSM-5 authors are concerned that legal standards differ so widely across the world that it would be problematic to use any criteria reflecting legal practices."