Depression and cognitive functioning in alcoholism

Studies on cognitive processes in alcoholism have reported changes with respect to executive functions and memory, which have been interpreted within the context of different neuropsychological models. The aims of the present study were to investigate (1) the validity of these models and (2) the influence of depression on cognitive functioning in alcoholism.

In the present investigation, patients suffering from alcoholism (Alc; n = 30), patients with depression but without alcoholism (Dep; n = 28) and healthy controls (HC; n = 28) were compared on a neuropsychological test battery.

The test battery included measurements of mood, memory and executive functions. The possible cumulative effect of alcohol and depression was analysed by comparison of depressed alcoholic patients (Dalc) and non-depressed alcoholic patients (NDAlc).

Group comparisons revealed impairments of alcoholic patients with respect to response inhibition, reasoning and free recall, irrespective of depression. Priming, short-term memory as well as verbal fluency abilities were unaffected. Depressive patients showed verbal fluency as well as free recall deficits. However, there was no difference in performance between depressed and non-depressed alcoholics.

The specific pattern of neuropsychological deficits of the alcoholic patients supports the frontal lobe hypothesis. The results of the present investigation suggest that these deficits are not generally exacerbated by comorbid depressive symptoms. Further studies, however, are desirable to investigate the relation between executive deficits and depression in alcoholics with evidence of major depression.