Endorsement of psychotic-like experiences and problematic cannabis use associated with worse executive functioning...

Emerging adults who endorse more positive psychotic-like experiences (PLEs; bizarre experiences, delusional ideations) may experience greater cannabis-related impairments in executive function. Negative and depressive PLEs are also associated with cannabis use, however, less is known about their relation to executive functioning. Here, we hypothesize that high positive PLEs and cannabis use are associated with worse performance on computerized versions of the Iowa Gambling Task (IGT) and the Card Sorting Task (CST); exploratory analyses are conducted with negative and depressive PLEs.

We recruited university students (N = 543) who completed an online study consisting of self-report measures of problematic cannabis use (Cannabis Use Disorder Identification Test; CUDIT-R) and PLEs (Community Assessment of Psychotic Experiences; CAPE). Of these, n=270 completed the CST and n=251 completed the IGT.

Problematic cannabis use and high endorsement of positive PLEs related to significantly worse performance on the IGT and greater perseverative errors on the CST. In addition, people who endorsed high levels of positive PLEs were also significantly more likely to complete the IGT with less money relative to those who endorsed fewer PLEs, regardless of cannabis use. Further analyses based on negative PLEs revealed a similar pattern for perseverative errors on the CST; depressive PLEs were not related to task performance.

Findings highlight that problematic cannabis use and more frequent and distressing positive PLEs are associated with poorer executive functioning. Thus, executive functioning may have implications for intervention among those high on both attributes, who are at high risk of onset of psychosis.