Phenylthiocarbamide (PTC) tasting in paranoid and nonparanoid schizophrenic patients.

The present study reports on the association between Phenylthiocarbamide tasting for paranoid and nonparanoid schizophrenic patients. The incidence of PTC tasting is highly variable, and tasters and nontasters are frequently associated with some pathological states. 25 paranoid and 25 nonparanoid schizophrenic patients were examined for their PTC taste sensitivity. Frequency of paranoid tasters resembles the distribution of the normal population, whereas the nonparanoid patients are significantly different in their taste thresholds, with a higher incidence of nontasters. The members of this latter group have twice the incidence of psychiatric illness in their family histories as those of the former group. The significance of these findings is discussed as related to vulnerability for schizophrenia.