Differences Between Treatment-Seeking and Nontreatment-Seeking Alcohol-Dependent Research Participants: An...

Alcoholism is a chronic relapsing disorder with complex behavioral and functional heterogeneity. To date, attempts to characterize subgroups of alcohol-dependent (AD) individuals have largely been focused on categorical distinctions based on behaviors such as ability to abstain, age of onset, and drinking motives, but these have failed to yield predictors of treatment response and disease course. The distinction between AD individuals who are or are not interested in treatment holds significant implications for interpreting results of human laboratory studies with nontreatment seekers and clinical trials with treatment-seeking AD patients. However, despite their crucial role in alcohol-related research, these 2 groups are poorly defined. In this exploratory analysis, we attempt to better define the phenotypic differences between these 2 experimentally relevant populations.

We analyzed data from AD individuals who participated in screening protocols to evaluate their suitability for participation in either treatment or nontreatment research studies at NIAAA. Scores on individual measures from a battery of behavioral, neuropsychological, and blood laboratory measures were compared between those who presented seeking treatment for AD and those who were not seeking treatment. Differences in each measure were assessed between the 2 groups. In addition, we explored whether significant differences were apparent when drinking behavior was used as a covariate.

Treatment seekers manifested more impairment compared to nontreatment seekers on a wide variety of measures in the following categories: alcohol drinking, personality, impulsivity, trauma/stress, cognition, aggression, mood, and liver enzyme tests. Treatment seekers endorsed a greater number of AD criteria. Several measures including elevations in liver enzyme tests remained significantly different between the 2 groups when average daily alcohol consumption per drinking day was used as a covariate.

Treatment-seeking, compared to nontreatment-seeking AD subjects who present for alcohol-related research studies, differ in characteristics beyond the quantity of alcohol consumption. Implications of these differences with respect to clinical research for treatments of AD are discussed.