The neuropsychological profiles of young psychosis patients with and without current cannabis use.

Introduction: Evidence suggests that patients with psychosis who have a history of cannabis use, but currently abstain, demonstrate superior cognitive performance than patients who have never used cannabis. The present study aimed to determine the neurocognitive profiles of patients who are in adolescence or early adulthood, when both illness- and drug-onset typically occur.

Methods: Subjects were 24 cannabis-using and 79 cannabis-naïve psychosis patients between 16 and 25 years of age.

Parcellating cognitive heterogeneity in early psychosis-spectrum illnesses: A cluster analysis.

Cognitive impairment is argued to represent a core feature of psychosis-spectrum illnesses. However, within-diagnosis heterogeneity is common, and risk factors for poor cognition remain to be examined after statistically accounting for heterogeneity. Accordingly, we used a data-driven technique (cluster analysis) to empirically-derive cognitive clusters across diagnoses and examined whether concurrent substance use or a history of a neurodevelopmental/behavioral disorder differed between clusters.

Meta-analysis of neurocognition in young psychosis patients with current cannabis use.

Objective: Adult psychosis patients (i.e. over the age of 25 years) who are also lifetime cannabis users (CANN±) appear to exhibit superior cognition compared to never-using patients (CANN-).