Schizophrenia - progressive and massive decline in response readiness by episodes

Objective: To relate the pattern of neuropsychological impairments among sc hizophrenic patients to case history data and disease characteristics in a cross-sectional study of unselected patients, and to integrate these data w ith two previous longitudinal studies of neuropsychological impairments amo ng schizophrenic patients. Method: One hundred consecutive schizophrenic patients were studied with re spect to clinical case history and current symptoms, medication and neurops ychological impairment using a comprehensive computerized test battery. Results: The most salient finding was a marked slowing of response readines s, linearly related to the number of previous acute episodes. The resulting deficit was far beyond what has been obtained in any other group of subjec ts (average -6 SD for > five episode patients). The impairments in many of the other neuropsychological parameters could to some extent be explained w ith reference to response slowing, with one exception - verbal short-term m emory. Adjustment for important confounding factors (age, duration of illne ss, medication) did not change the strong negative association between resp onse readiness and number of previous episodes. Conclusion: These findings, together with findings of our two previous long itudinal studies and a recent replication, prompted us to suggest that each acute schizophrenic episode inflicts damage to a set of hypothetical struc tures, cognitive pattern generators. We assume that these structures transl ate intentions to logistic programs. When damaged, delays are introduced in to executive functions and corollary discharge processes will run out of ph ase with intentions. This model implicates new ways of looking at the gener ative mechanisms of the illness, and on treatment strategies.