Verbal learning and memory and psychopathology in schizophrenia

Verbal learning and memory (VLM) are the most impaired cognitive functions noted in schizophrenia. Though its association with negative symptoms is found consistently, only few have compared this relationship at a drug free/naïve state and on antipsychotic medications. Thus the aim of the study was to compare VLM functions in schizophrenia and normal controls and find its association between negative symptoms at drug free/naïve state and on antipsychotic medication.

A sample of 78 initially drug naïve/free patients of schizophrenia of either sex, aged between 18 and 45 years, and 30 age, sex and education matched normal controls were assessed for VLM by Rey-Auditory-Verbal-Learning-Test (RAVLT). The schizophrenia group was assessed at baseline and at the end of six weeks treatment with RAVLT and for positive, negative and depressive symptoms.

The schizophrenia group performed significantly poorly on VLM at both time points compared to normal controls, though significant improvement in the schizophrenia group was noted following six weeks treatment. Only negative symptoms inversely correlated with immediate memory span and verbal learning at baseline and in addition verbal memory at six weeks, while change in any of the dimensions of psychopathology (assessed in terms of positive, negative and depressive symptoms) over six weeks did not correlate with change in measures of cognitive functions.

For VLM deficits in schizophrenia, though correlated with negative symptoms, improvement with treatment could not be attributed to improvement in psychopathology.