raclopride and Schizotypal-Personality-Disorder

Previous research has suggested that schizotypal personality disorder (SPD), a condition that shares clinical and cognitive features with schizophrenia, may be associated with elevated striatal dopamine functioning; however, there are no published studies of dopamine release within subregions of the striatum in SPD.. To characterize dopamine release capacity in striatal subregions and its relation to clinical and cognitive features in SPD.. We used positron emission tomography with [. There were no significant group differences in BP. In contrast to previous findings, SPD was not associated with elevated striatal dopamine release. However, in SPD, there was a moderate positive association between ventral striatal dopamine release and severity of cognitive-perceptual symptoms, and negative associations between striatal dopamine release and severity of disorganized symptoms. Future larger scale investigations that allow for the separate examination of subgroups of participants based on clinical presentation will be valuable in further elucidating striatal DA functioning in SPD.

Topics: Adolescent; Adult; Amphetamine; Corpus Striatum; Dopamine; Dopamine Uptake Inhibitors; Female; Humans; Male; Memory, Short-Term; Middle Aged; Positron-Emission Tomography; Raclopride; Receptors, Dopamine D2; Schizotypal Personality Disorder; Young Adult

Drugs that increase dopamine levels in the brain can cause psychotic symptoms in healthy individuals and worsen them in schizophrenic patients. Psychological stress also increases dopamine release and is thought to play a role in susceptibility to psychotic illness. We hypothesized that healthy individuals at elevated risk of developing psychosis would show greater striatal dopamine release than controls in response to stress. Using positron emission tomography and [(11)C]raclopride, we measured changes in synaptic dopamine concentrations in 10 controls and 16 psychometric schizotypes; 9 with perceptual aberrations (PerAb, ie positive schizotypy) and 7 with physical anhedonia (PhysAn, ie negative schizotypy). [(11)C]Raclopride binding potential was measured during a psychological stress task and a sensory-motor control. All three groups showed significant increases in self-reported stress and cortisol levels between the stress and control conditions. However, only the PhysAn group showed significant stress-induced dopamine release. Dopamine release in the entire sample was significantly negatively correlated with smooth pursuit gain, an endophenotype linked to frontal lobe function. Our findings suggest the presence of abnormalities in the dopamine response to stress in negative symptom schizotypy, and provide indirect evidence of a link to frontal function.

Topics: Adult; Dopamine; Dopamine Antagonists; Female; Frontal Lobe; Hormones; Humans; Linear Models; Male; Maternal Behavior; Neostriatum; Neuropsychological Tests; Positron-Emission Tomography; Psychiatric Status Rating Scales; Psychotic Disorders; Pursuit, Smooth; Raclopride; Radiopharmaceuticals; Receptors, Dopamine D2; Risk; Schizotypal Personality Disorder; Stress, Psychological