Schizotypy trait and striatal dopamine receptors in healthy volunteers

Individuals with schizotypal features exhibit cognitive, perceptual and social deficits that are similar to but less prominent than those seen in patients with schizophrenia. Dopaminergic hyperactivity in the striatum has been related to the positive symptoms of schizophrenia, and brain-imaging studies of dopamine uptake in the striatum are thought to be linked to the pathophysiological mechanisms underlying schizophrenia. The aim of this study was to investigate whether the increased availability of striatal dopamine (DA) D _2/3 receptors is related to elevated levels of schizotypal features in healthy individuals. The Schizotypal Personality Questionnaire (SPQ) was administered to 55 healthy volunteers. The availability of their striatal DA D _2/3 receptors was analysed using [ ¹²³I] iodobenzamide single photon emission computed tomography (SPECT). Although the SPQ total scores showed no correlation with the availability of total (left and right) striatal DA D ₂ receptors, the SPQ disorganised subscale scores were positively correlated with the availability of right striatal DA D _2/3 receptors. Our findings demonstrated that the availability of striatal DA D _2/3 receptors may be associated with schizotypal features in healthy volunteers.