Neuropsychological Abnormalities Associated with Alcohol Dependence During Long-Term Rehabilitation Treatment of German Inpatients.

Background: Alcohol dependence is associated with several neuropsychological abnormalities, such as increased impulsivity or attentional bias towards drug-related stimuli. However, it is debated whether these abnormalities are on the decline after long-term abstinence from alcohol. Inpatient rehabilitation treatment enables the longitudinal investigation of such variables during a long, largely secured, period of abstinence.

Methods: This study involved alcohol-dependent patients consecutively admitted for a duration of 14-26 weeks to an inpatient rehabilitation treatment center located in a hospital specializing in substance use disorders. Craving and impulsivity were assessed with the means of two questionnaires (e.g., OCDS-G and BIS-11); conversely, attentional bias and problems with inhibition were measured with the help of two computer-based experiments (e.g., dot-probe task and stop-signal-reaction task). Investigations were conducted at entry, after 6 weeks, and during the last two weeks of the inpatient treatment.

Results: A total of 130 patients with alcohol dependence (mean age 43.3 years; 78.5% male) completed the first, N = 102 the second, and N = 83 the final assessment. Over the whole period of inpatient treatment, there was a significant decrease in patients' scores for both craving (t(83) = 7.8, p < 0.001) and impulsivity (t(82) = -3.75, p < 0.001, t(82) = 4.4, p < 0.001). However, there were no significant changes regarding attentional bias (t(82) = 0.16, p = 0.494) and inhibitory control (t(76) = 0.04, p = 0.482) scores.

Conclusions: Neuropsychological abnormalities associated with alcohol dependence might persist even after a long abstinence period. The decrease in both craving and impulsivity levels may be explained by the protected, alcohol-free, hospital environment; however, patients' risk of post-discharge relapse may remain high, as the basic neurobiological mechanisms of alcohol dependence may persist for long periods, and possibly for more than 3-6 months.