Attenuated niacin-induced skin flush response in individuals with clinical high risk for psychosis

Background Im paired sesitwity of he soin Mlush response bo miacin is one of the most rpicated findngs in patents with schizoprenia Howewer.prior studies have usaly focused on postonset psychusis,and ll is knowm about the dinical high-risk(CHR)phase of niacin senstity in psychosis Aims To proftle and compare the miacin flush responsge among CHR individuals(converters and non-coverters)patients with frstepso schinophrenia(FES)and healty controls(HCs).Methods Sensivily 1o ftour concentralions (0.1-0001M)of aqueous methylnicotinate was tested in 105 CHR individuals,57 patients with FES and 52 HCs.CHR individuals were further grouped as converters and non converters according to the 2-year follow-up outcomes.Skin flush response scores were rated on a 4-point scale.Results Of the 105 CHR individuals,21 individuals were lost during the study,leaving 84 CHR individuals;16(19.0%)converted to full psychosis at 2 years of fllow-up.Flush response scores identifed in the CHR samples were characterised as modest degree levels,intermediate between those of HC individuals and patients with FES.The flush responses in the CHR group mimicked the responses observed in the FES group at higher concentrations(0.01 M,0.1 M)and longer time points(15 min,20min);however,these became comparable vith the responses in the HC group at the shorter time points and at lower concentr ations.The converters exhibited lower mean flush response scores than the non-converters.Conclusions Attenuated niacin-induced flushing emerged during the early phase of psychosis.New devices should be developed and verified for objective quantification of skin responses in the CHR population.