The average striatal [18F]CFT binding potentials were almost identical in the comparison and patient groups: mean=4.50 (SD=0.54) and mean=4.56 (SD=0.57), respectively, in the caudate (t=–0.24, df=16, p=0.81, independent-samples t test); and mean=4.81 (SD=0.41) and mean=4.86 (SD=0.59) in the putamen (t=–0.20, df=16, p=0.84, independent-samples t test). However, two-way ANOVAs indicated a significant interaction between group and hemisphere in the caudate (F=10.00, df=1, 16, p=0.01 but not in the putamen (F=1.67, df=1, 16, p=0.21) (F1). Post hoc paired t tests revealed significantly higher (6.7%) [18F]CFT binding in the right caudate than in the left in the comparison group: mean=4.64 (SD=0.62) and mean=4.35 (SD=0.48) in the right and left caudate, respectively (t=3.50, df=8, p=0.01). In the schizophrenic group, no asymmetry was found: mean=4.53 (SD=0.58) and mean=4.59 (SD=0.59) in the right and left caudate (t=–0.75, df=8, p=0.48). No asymmetry was seen in the putamen in either group. The total duration of the illness, but not the duration of active illness, correlated with [18F]CFT binding in the putamen (r=–0.77, df=6, p=0.03, ANCOVA, with age as a covariate) but not in the caudate. None of the [18F]CFT uptake parameters correlated with any of the rated symptom dimensions.