IQ differences between patients with first episode psychosis in London and Palermo reflect differences in patterns of cannabis use

摘要

Aims: Cognitive impairment is a possible indicator of neurodevelopmental impairment, but not all psychotic patients are cognitively compromised. It has been suggested that heavy cannabis use may precipitate psychosis in those who show no such compromise. This study compares two samples of patientswith first-episode psychosis and their respective non-psychotic controls, in London (UK) and Palermo (Italy), and examineswhether different patterns of cannabis use are reflected in differences in IQ.