Premorbid IQ subgroups in first episode non affective psychosis patients: Long-term sex differences in function and neurocognition.

Background: Low IQ has been associated with schizophrenia, even to the point of being posited as a possible causal factor for psychosis. However, individuals with normal and high IQ also develop psychotic illnesses. The aim of this study was to characterize premorbid IQ subgroups at first episode of psychosis (FEP).