The Stability of Intellectual Function in Chronic Schizophrenia

Intelligence tests on 49 chronic schizophrenics, followed by retests 8 and 14 years later, fail to support the concept of progressive loss in intellectual function. When allowances are made for normal aging, IQs increase significantly. The results hold for both paranoid and nonparanoid patients and for verbal and nonverbal tests. The stability of intelligence with continuing psychosis cannot be attributed to practice or to sample attrition. Chronic patients who improve in symptoms and in social adequacy show appreciable gains in test scores. The evidence on mean changes suggests that the severity of psychosis may decrease over the years, thus counteracting effects of old age and long hospitalization. The concept of deterioration might well be deemphasized, with more attention directed to the environmental and behavioral determinants of deficit reversal.