Cannabis use, schizotypy, and attentional inhibition: a longitudinal study

Abstract

Cannabis use has been linked to higher levels of schizotypy, a multidimensional personality construct related to psychosis risk. Cannabis use has also been associated with deficits in attentional inhibition – the ability to ignore distracting information and hence focus attention on a target or goal. Previous research suggests that these associations are most apparent in the case of regular, early-onset adolescent cannabis use. The causal direction of associations, however, remains in question. The current study aimed to examine the association between cannabis use with schizotypy and attentional inhibition over time. Participants were 324 young people aged 14-24 years who were assessed at three time-points: baseline, 6 months, and 12 months. Assessments were delivered online, and included questions on cannabis and other drug use, schizotypy (measured using the OLIFE), as well as a location-based negative priming task to measure attentional inhibition. Frequent cannabis use was associated with deficits in attentional inhibition among females only. Younger frequent users of cannabis showed higher levels of negative schizotypy at the 12-month follow-up point compared to older frequent users. Cannabis use was not associated with positive schizotypy over time. The current findings have important implications for understanding how cannabis use may influence the neurodevelopment of reward-related brain functions as well as highlight potential sex-related differences in relation to the effects of cannabis use on cognition.