BACKGROUND: Using positron emission tomography (PET), we previously observed increases in 3,4-dihydroxy-6-[(18)F]fluoro-L-phenylalanine ((18)F-DOPA) uptake in the striatum of subjects at ultra-high risk (UHR) for psychosis, indicating elevated presynaptic dopamine synthesis capacity. The purpose of this study was to test if this finding would be replicated in a second UHR cohort. METHODS: (18)F-DOPA PET was used to estimate dopamine synthesis capacity in the striatum of an entirely new cohort of 26 individuals at UHR for psychosis (14 males, mean±SD age = 22.7±4.7 years) and 20 healthy volunteers matched for age and gender (11 males, mean±SD age = 24.5±4.5 years). RESULTS: Dopamine synthesis capacity was elevated in the whole [t(44) = 2.6; p = .01, effect size = .81] and associative striatum [t(44) = 2.6; p = .01, effect size = .73] of UHR compared with control subjects. When the two samples were combined to give a final sample of 32 control and 50 UHR subjects, the higher levels of dopamine synthesis capacity in the UHR group reached significance across the whole [F(1,81) = 11.0; p = .001], associative [F(1,81) = 12.7; p = .001], and sensorimotor [F(1,81) = 4.7; p = .03], but not the limbic [F(1,81) = 2.1; p = .2], striatum. CONCLUSIONS: The findings indicate that elevated dopamine synthesis capacity in the dorsal striatum is a robust feature of individuals at UHR for psychosis and provide further evidence that dopaminergic abnormalities precede the onset of psychosis.
BACKGROUND: Using positron emission tomography (PET), we previously observed increases in 3,4-dihydroxy-6-[(18)F]fluoro-L-phenylalanine ((18)F-DOPA) uptake in the striatum of subjects at ultra-high risk (UHR) for psychosis, indicating elevated presynaptic dopamine synthesis capacity. The purpose of this study was to test if this finding would be replicated in a second UHR cohort. METHODS: (18)F-DOPA PET was used to estimate dopamine synthesis capacity in the striatum of an entirely new cohort of 26 individuals at UHR for psychosis (14 males, mean±SD age = 22.7±4.7 years) and 20 healthy volunteers matched for age and gender (11 males, mean±SD age = 24.5±4.5 years). RESULTS:Dopamine synthesis capacity was elevated in the whole [t(44) = 2.6; p = .01, effect size = .81] and associative striatum [t(44) = 2.6; p = .01, effect size = .73] of UHR compared with control subjects. When the two samples were combined to give a final sample of 32 control and 50 UHR subjects, the higher levels of dopamine synthesis capacity in the UHR group reached significance across the whole [F(1,81) = 11.0; p = .001], associative [F(1,81) = 12.7; p = .001], and sensorimotor [F(1,81) = 4.7; p = .03], but not the limbic [F(1,81) = 2.1; p = .2], striatum. CONCLUSIONS: The findings indicate that elevated dopamine synthesis capacity in the dorsal striatum is a robust feature of individuals at UHR for psychosis and provide further evidence that dopaminergic abnormalities precede the onset of psychosis.
Authors: Daniel P Eisenberg; Philip D Kohn; Catherine E Hegarty; Angela M Ianni; Bhaskar Kolachana; Michael D Gregory; Joseph C Masdeu; Karen F Berman Journal: Neuropsychopharmacology Date: 2016-02-29 Impact factor: 7.853
Authors: Marco Colizzi; Conrad Iyegbe; John Powell; Gianluca Ursini; Annamaria Porcelli; Aurora Bonvino; Paolo Taurisano; Raffaella Romano; Rita Masellis; Giuseppe Blasi; Craig Morgan; Katherine Aitchison; Valeria Mondelli; Sonija Luzi; Anna Kolliakou; Anthony David; Robin M Murray; Alessandro Bertolino; Marta Di Forti Journal: Schizophr Bull Date: 2015-03-31 Impact factor: 9.306