A Multimodal Imaging Study of Dopamine in Early Psychosis

The development of new treatments for psychosis, a psychiatric condition that is prevalent and highly disabling despite antipsychotic medications, has been limited, in part, by a lack of information from brain imaging studies during the period that leads to the development of psychotic symptoms. In this project the investigators will use Positron Emission Tomography (PET) and neuromelanin-sensitive magnetic resonance imaging (NM-MRI) to examine a brain chemical that is involved in schizophrenia called dopamine and where it first becomes abnormal. The investigators will use multimodal PET/MR imaging (i.e., \[11C\]raclopride w/MPH challenge and NM-MRI) in the same CHR patients. The investigators will recruit 115 clinical high risk individuals. All subjects will undergo \[11C\]raclopride w/methylphenidate challenge and neuromelanin-MRI imaging along with clinical assessments. Patients will be followed every 3 months for two years or until conversion to psychosis, whichever comes first, to assess for conversion to psychosis and clinical outcomes.