Neurocognitive dysfunction in patients diagnosed with schizophrenia and alcoholism

The authors administered the Halstead-Reitan Neuropsychological Test Battery to schizophrenic groups with (n = 54) and without (n = 217) coexisting alcoholism, nonschizophrenic groups with alcoholism (n = 231), and a patient comparison group (n = 145) to determine the extent of additive cognitive impairment in schizophrenia associated with alcoholism and to compare cognitive function in alcoholism and schizophrenia. The additive effects of alcoholism on cognitive dysfunction in schizophrenia were subtle but were consistently identifiable. Cognitive dysfunction in alcoholism was less severe than in schizophrenia with or without alcoholism. The magnitude of additive effects of alcoholism on cognitive dysfunction in schizophrenia was age related with a significant interaction between age and presence or absence of alcoholism on a global index of cognitive dysfunction.