Neurocognitive functioning in recently abstinent, cocaine-abusing schizophrenic patients

Purpose. This report examined a broad range of cognitive functioning in a group of recently abstinent, cocaine-abusing schizophrenic patients (CA + SZ). Methods. Measures of selective and sustained attention, learning and memory, and executive functioning were administered to CA + SZ patients within 72 h of last cocaine use. A comparison group of non-substance-abusing schizophrenic patients (SZ) presenting for inpatient psychiatric treatment were also examined in an identical time frame. We hypothesized that the neurobiological impact of cocaine abuse and acute abstinence would cause CA + SZ to manifest deficits in all domains of cognitive functioning relative to non-abusing SZ patients. Results. Results revealed that CA + SZ displayed significant memory impairment relative to their non-abuser SZ counterparts. No group differences, however, were detected on any other neurocognitive measure. CA + SZ were able to selectively process digit strings during the presence and absence of distracting stimuli, sustain attention, and perform executive functions at performance levels equal to their non-abuser SZ counterparts. Implications. These results are consistent with many past studies that have found CA + SZ patients to manifest memory impairment but have relatively well perserved functioning in other cognitive domains. The results are discussed in terms of the biological concomitants of cocaine abuse and acute abstinence in schizophrenia.