Working memory in schizophrenia

Background: Working memory has been reported to be impaired in schizophrenia, but there are inconsistencies in the literature. Therefore, we undertook the current study with the objective of assessing both auditory and visuospatial working memory tasks in a sample of schizophrenia patients in comparison to normal controls, and its correlation with psychopathology. Method: The sample comprised of 78 drug naive or drug free patients of either sex, aged between 18-45 years, fulfilling diagnosis of schizophrenia according to ICD-10 Diagnostic Criteria for Research, and 35 age, sex and education matched normal controls. SAPS and SANS were used to assess positive and negative symptoms in patients, respectively. To assess working memory, Letter-Number Sequencing and Spatial Span subtests of Wechsler Memory Scale, Third edition (WMS-III) were used. Results: There were significantly lower scores in schizophrenia patients compared to normal controls in spatial span forward (p<.001, Cohen's d = 2.51), backward (p<.001, Cohen's d = 2.62) and total scores (p<.001, Cohen's d = 2.78) as well as letter-number sequencing scores (p<.001, Cohen's d = 1.87). In the patient group, there was significant negative correlation between SANS total score with spatial span forward (τ = -.227, p<.01) and total scores (τ = -.164, p<.05). Conclusion: Our study suggests impairment of both visuospatial as well as auditory memory in patients of schizophrenia as compared to controls. Furthermore, visuospatial working memory correlated inversely with negative symptoms.