[18F]Fluortriopride

Preclinical work suggests that D3 dopamine receptors may be important in the study of the pathophysiology of affective disorders, psychotic disorders and addiction. D3 receptors may also play a role in dystonia, Parkinson's disease and response to treatment of these disorders. However, there has been a lack of specific radioligands for imaging D3 receptors. This proposed protocol will evaluate the uptake of [18F]FTP as a more specific in vivo measure of D3 receptor binding in the brain in healthy volunteers subjects after injection of lorazepam vs placebo, and in cocaine-dependent subjects. Test-retest scans will evaluate the variability of [18F]FTP uptake measures in both healthy volunteer subjects and cocaine-dependent subjects.