biostudies-literatureWengler KNIMH NIH HHS198-208https://www.ebi.ac.uk/biostudies/studies/S-EPMC10633403biostudies-literatureUnknown81(2)<h4>Importance</h4>The link between psychosis and dopaminergic dysfunction is established, but no generalizable biomarkers with clear potential for clinical adoption exist.<h4>Objective</h4>To replicate previous findings relating neuromelanin-sensitive magnetic resonance imaging (NM-MRI), a proxy measure of dopamine function, to psychosis severity in antipsychotic-free individuals in the psychosis spectrum and to evaluate the out-of-sample predictive ability of NM-MRI for psychosis severity.<h4>Design, setting, and participants</h4>This cross-sectional study recruited participants from 2019 to 2023 in the New York City area (main samples) and Mexico City area (external validation sample). The main samples consisted of 42 antipsychotic-free patients with schizophrenia, 53 antipsychotic-freeJAMA psychiatryGeneralizability and Out-of-Sample Predictive Ability of Associations Between Neuromelanin-Sensitive Magnetic Resonance Imaging and Psychosis in Antipsychotic-Free Individuals.PMC10633403R01 MH114965R01 MH110270F32 MH125540R01 MH117323Velikovskaya ALee SBaker SCGirgis RROjeil NWengler Kde la Fuente-Sandoval CFogelson AReyes-Madrigal FHorga GfalseGeneralizability and Out-of-Sample Predictive Ability of Associations Between Neuromelanin-Sensitive Magnetic Resonance Imaging and Psychosis in Antipsychotic-Free Individuals.<h4>Importance</h4>The link between psychosis and dopaminergic dysfunction is established, but no generalizable biomarkers with clear potential for clinical adoption exist.<h4>Objective</h4>To replicate previous findings relating neuromelanin-sensitive magnetic resonance imaging (NM-MRI), a proxy measure of dopamine function, to psychosis severity in antipsychotic-free individuals in the psychosis spectrum and to evaluate the out-of-sample predictive ability of NM-MRI for psychosis severity.<h4>Design, setting, and participants</h4>This cross-sectional study recruited participants from 2019 to 2023 in the New York City area (main samples) and Mexico City area (external validation sample). The main samples consisted of 42 antipsychotic-free patients with schizophrenia, 53 antipsychotic-free2024-01-01T00:00:00Z2024 Feb2026-07-16T13:21:23.333Z2026-07-09T10:56:36.349ZS-EPMC106334033793884710.1001/jamapsychiatry.2023.4305