Declarative and nondeclarative memory in schizophrenia: What is impaired? What is spared?

The study's aim was to assess a broad range of declarative and nondeclarative memory functions in schizophrenia to identify areas of impairment versus relative preservation. Participants included 40 schizophrenia outpatients and 30 demographically comparable community residents. All participants were administered a battery assessing declarative memory (verbal learning, working memory, semantic memory, remote memory, verbal retention) and nondeclarative memory (procedural learning, priming). To control for order effects, the battery was divided into three parts of approximately equal length with order of administration counterbalanced across study participants. The results showed persons with schizophrenia to be significantly impaired relative to community residents in verbal learning, working memory, semantic memory, remote memory, and priming. In contrast, the two groups were comparable in verbal retention and procedural learning. In the schizophrenia group, priming ability best discriminated past year's vocational status. In sum, the findings indicate a specific pattern of impairment and preservation of memory functioning in schizophrenia. Skill (procedural) learning and retention of learned, declarative verbal information across a delay appear intact, while all other areas measured appear impaired.