Distal colon motility in schizophrenic patients.

Although the dopaminergic blocking agents (DBA) haloperidol and sulpiride strongly inhibit distal colon motility in most nonpsychotic subjects (83 per cent), this effect was registered in only 10 per cent of the 30 schizophrenic patients investigated in the present study. In these cases, only sulpiride (an "atypical" DBA) displayed distal colon motility inhibition in schizophrenic subjects. When haloperidol (a "classical" DBA) produced any modification (in 23.3 per cent), this was rather in the nature of an increase in motility. All these cases showed low or absent distal colon motility during preinjection periods. the fact that three different types of antinoradrenergic drugs (dihydroergotamine, phentolamine, and clonidine), but not DBA, inhibited distal colon motility in 90 per cent of the schizophrenic subjects suggests the existence of an overactivity of the noradrenergic system at this peripheral level.