Nithsdale schizophrenia surveys 21: a longitudinal study of National AdultReading Test stability

Background. The stability of the National Adult Reading Test (NART) as a me asure of pre-morbid intelligence in schizophrenia has not yet been satisfac torily established despite the widespread use of the NART in schizophrenia research. Method. We examined NART stability in a diverse group of 45 schizophrenic p atients in a prospective longitudinal study over 6.5-7.5 years. Results. The results showed that NART performance does not decline signific antly with increasing duration of schizophrenic illness and that test-retes t reliability, even over 6.5-7.5 years, is extremely high. Discussion. Our results provide the necessary evidence that the NART can be used as a stable measure of pre-morbid intelligence in schizophrenia.