Assessment of frontal lobe functions in schizophrenia, depression and alcohol dependence

Abstract

Objective: Schizophrenia, depression and alcohol dependence are major psychiatric diagnostic disorders that have a tendency for a chronic course. The effects of these disorders on brain structure and associated cognitive functions have been studied. The aim of this study was examine frontal lobe functions with two neuropsychological tests, which have been thought to be sensitive to frontal lobe dysfunction. Method: The sample consisted of 160 subjects, 40 in each of the diagnostic groups and a control group. The ages of the subjects varied between 20 and 55. Neurocognitive characteristics were assessed by Wisconsin Card Sorting Test (WCST) and Stroop Test-TBAG Form (ST-TBAG). Subjects with extreme scores were not included in statistical analyses. Since an influence of education and age on the scores was observed, analyses of covariance were used for the statistical analyses, in which the education and age were entered as a covariate variable. Results: The statistical results showed significant differences between the groups for the WCST total number of errors (WCST 2), number of completed categories (WCST 4), number of scores concerned with perseveration (WCST 5, 6, 7, 8), number of scores concerned with conceptual level responses (WCST 10 and 11) and the duration of time evaluations in ST (ST 1a, 3a, 4a and 5a). Conclusion: In general, the findings of cognitive functions in schizophrenia and alcohol dependence were similar, and the scores of both were lower than in the depression and control group.