Neurocognitive functioning and quality of life among dually diagnosed and non-substance abusing schizophrenia inpatients.

The aim of this study was to compare the domains of intellectual, memory and executive functions of persons with schizophrenia who concurrently have substance abuse disorders (the dually diagnosed) with a group of non-substance-abusing patients with schizophrenia and to ascertain if there were differences between the two groups in their perceptions of quality of life. Neuropsychological and quality of life data of 46 dually diagnosed and 43 non-substance-abusing patients with schizophrenia was analysed retrospectively. All subjects were inpatients of a state psychiatric hospital. Selected subtests of the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale-III constituted the intellectual and memory measures whilst the measures of executive functioning were the Stroop Color Word Test, the FAS version of the Controlled Oral Word Association Test, and the Trail Making Test (Trails A & B). Perceptions of quality of life were evaluated using the World Health Organization Quality of Life measure. The two groups did not differentiate on intellectual and memory domains, however, the dually diagnosed showed a significantly better facility with tasks of executive functions. In addition, the dually diagnosed expressed higher levels of satisfaction with their quality of life compared to the non-substance-abusing patients with schizophrenia. These results have implications for interventions.