Relations between neuropsychological vulnerability markers and negative symptoms in schizophrenia

In neuropsychological vulnerability research the visual backward masking task, the Span of Apprehension, the degraded stimulus Continuous Performance Test (dsCPT), and the Wisconsin Card Sorting Test have been described as putative indicators for the predisposition to develop negative (schizophrenic) symptoms. The present study assesses the stability of the association between neuropsychological tests and negative symptoms by examining clinically improved patients. The interdependence between the four cognitive measures and clinical symptomatology was examined in 31 patients with DSM III-R and ICD-10 schizophrenia suffering predominantly from negative symptoms. Backward masking performance was related to affective flattening and anxiety-depression. False alarm rate on dsCPT was associated positively with affective flattening and hallucinations, and negatively with avolition. Card sorting preseverative errors correlated negatively with anhedonia, non-preservative errors correlated positively with avolition. Correlations notwithstanding, the data provide evidence in support of the relative independence of neuropsychological functions and negative symptoms in clinically improved schizophrenics.