Increased Hippocampal Blood Flow in People at Clinical High Risk for Psychosis and Effects of Cannabidiol
Hippocampal hyperperfusion has been observed in people at Clinical High Risk for Psychosis (CHR), is associated with adverse longitudinal outcomes and represents a potential treatment target for novel pharmacotherapies. Whether cannabidiol (CBD) has ameliorative effects on hippocampal blood flow (rCBF) in CHR patients remains unknown. Using a double-blind, parallel-group design, 33 CHR patients were randomised to a single oral 600mg dose of CBD or placebo; 19 healthy controls did not receive any drug. Hippocampal rCBF was measured using Arterial Spin Labelling. We examined differences relating to CHR status (controls vs placebo), effects of CBD in CHR (placebo vs CBD) and linear between-group relationships, such that placebo>CBD>controls or controls>CBD>placebo, using a combination of hypothesis-driven and exploratory wholebrain analyses.