Impulsivity and Alcohol Dependence Treatment Completion: Is There a Neurocognitive Risk Factor at Treatment Entry?

Abstract

Although there is considerable support for the relationship between impulsivity and alcohol dependence, little is known about the impact of neurocognitive aspects of impulsivity on treatment outcome. The aim of this study was to prospectively investigate the impact of neurocognitive impulsivity at treatment onset on treatment completion. Forty-three alcohol-dependent patients entering inpatient treatment for alcohol dependence completed neurocognitive measures of impulsivity at the beginning of treatment. Assessments included prototypical measures of impulsive action (Go/No-go task [GNG] and Stop Signal Task [SST]) and impulsive choice (Delay Discounting Test [DDT], and Iowa Gambling Task). According to treatment outcomes, patients were divided into a patient group with regular treatment completion (e.g.,with planned discharges, and without relapse during treatment) or irregular treatment course (e.g., premature and unplanned termination of treatment, "dropout," and/or relapse). Results show that, relative to patients completing treatment in a regular fashion (regular treatment completers [RTC]; 67%), those with an irregular course of treatment (relapse and/or dropout) (irregular treatment completers [ITC]; 33%) had significantly poorer GNG response inhibition performance (p=0.011), and showed a trend toward greater delay discounting (DDT; p=0.052) at treatment onset. Additional logistic regression analyses identified poor GNG response inhibition performance as a significant predictor for an irregular treatment course (GNG: p=0.021; DDT: p=0.067), particularly for relapse (GNG: p=0.023). Neurocognitive impulsivity impacts upon treatment completion and appears sensitive for the prediction of relapse and dropout in alcohol-dependent patients. Poorer GNG response inhibition and a tendency toward steeper discounting of delayed rewards should be regarded as neurocognitive risk factors, which can be identified early in the course of alcohol dependence treatment.