Memory deficits in patients with schizophrenia: preliminary data from the Wechsler Memory Scale-Third Edition support earlier findings.

OBJECTIVE: To determine whether memory data presented for a schizophrenia sample in the Technical Manual of the Wechsler Memory Scale-Third Edition support trends identified in a previously published review of studies employing an earlier version of the instrument, the Wechsler Memory Scale-Revised.
DESIGN: Archival: reformulation of published data. PATIENTS: Patients with schizophrenia, Alzheimer's disease, Korsakoff's syndrome or traumatic brain injury (TBI) for whom intelligence and memory data were reported in the Technical Manual of the Wechsler Adult Intelligence Scale-Third Edition Wechsler Memory Scale-Third Edition (WAIS-III WMS-III). OUTCOME MEASURES: Mean Full Scale, Verbal, and Performance Intelligence Quotients of the WAIS-III and mean WMS-III Immediate and General Memory Indexes. Single-trial learning and learning slope data were also culled from the WAIS-III WMS-III Technical Manual.
RESULTS: Memory indexes for patients with Alzheimer's disease or Korsakoff's syndrome were substantially lower than those for patients with schizophrenia or TBI. In tests of learning processes, patients with schizophrenia had an inferior ability to repeat material presented just once, in comparison with the standardization sample. However, they did relatively better with repeated presentations than patients with Alzheimer's disease or Korsakoff's syndrome. The learning slope for patients with schizophrenia demonstrated an ability to absorb and consolidate increasing amounts of material with repeated exposure that is inconsistent with pronounced memory impairment.
CONCLUSIONS: Although patients with schizophrenia exhibit new learning deficiencies, their memory capabilities are not substantially weaker than their general intellectual abilities, and do not approach the memory impairment exhibited by patients with Alzheimer's disease or Korsakoff's syndrome.