The nature of intellectual deficit in schizophrenia. I. A comparison of schizophrenics and neurotics.
Impairment was non-progressive and largely confined to the period between the onset of the illness and first admission, with catatonics showing the most differential impairment of intellectual ability.
Abstract
Progressive Matrices (1938) and Mill Hill Vocabulary scores of 270 schizophrenics were analysed in relation to sex, length of hospitalization, age and diagnostic subgroup. Men were significantly superior to women in all subgroups on both tests. Hospitalization period contributed little to the results over and above its inevitable relationship with age. The negative relationship between PM scores and age was similar in schizophrenics and neurotics. This and other evidence led to the conclusion that impairment was non-progressive and largely confined to the period between the onset of the illness and first admission. Consistent differences were found between the subgroups independent of the sex difference, catatonics showing the most differential impairment of intellectual ability.