[Sensitivity and specificity of a neuropsychological instrument in the evaluation of schizophrenia subtypes: a study with a Spanish speaking population]

Cognitive impairment is a prominent feature of schizophrenia that correlates with functional outcome. In the clinical practice and research, there is a need to count on brief, reliable and standardized instruments to evaluate the cognitive profile in psychiatric, geriatric and neurological patients. There are only a few standardized and validated instruments with the Hispanic population, so the adaptation and validation of instruments become a high relevance issue. The Brief Neuropsychological Test in Spanish (NEUROPSI) is a brief neuropsychological battery evaluating a wide spectrum of cognitive functions and standardized with Spanish speaking population according to age and educational level. The purpose of the present study was to determine the sensitivity and specificity of this instrument for its clinical use in patients with schizophrenia, as well as in distinct subtypes of schizophrenic patients: positive, negative and mixed.We studied a total sample of 60 subjects (30 patients with schizophrenia and 30 matched controls). Using the total score we found 87.5 % sensitivity and 92.8% specificity. A discriminant analysis using the 25 subtest scores of the NEUROPSI accurately classified 83.3 % of the sample. None of the control subjects was classified as patient.Classification by subtype showed 80 % of patients with negative symptoms, 90 % of patients with positive symptoms and 70 % of patients with mixed symptoms.The accurate diagnosis of cognitive dysfunction in schizophrenic patients could help in management as well as development of more specific pharmacological treatment for each schizophrenic subtype.