The observer interaction variable in evaluation of socialising properties of pimozide (Orap).

Eighteen chronic, institutionalised patients were randomly assigned to two groups for the purpose of a double blind trial of pimozide (Orap). The results of the study indicated an increase in socialisation, as measured by the Venables scale, for both groups, and no significant difference in this variable between placebo and active preparation groups. It is suggested that greater observer interaction may be responsible for the observed increase in socialisation previously attributed to pimozide.