Neurocognitive moderation of associations between cannabis use and psychoneuroticism

Background: Cannabis use has been associated with neurocognitive impairments and psychopathology. The strength of such associations does however appear to depend on many different factors, such as duration and intensity of use, but also differential susceptibility due to genetic make-up and environmental influences. The present study investigated whether specific cognitive weaknesses moderated associations between cannabis use and psychoneuroticism, which may be considered one of the "softer" expressions of an extended psychosis phenotype. Method: One hundred and fifty (150) young adults (mean age: 24.7 years, SD: 3.7), mostly college students, performed three computerized neuropsychological tasks: a relatively easy social perception task (Face Recognition), a more complex social perception task combining emotion recognition and executive functioning (Matching Facial Emotions), and a more complex task requiring sustained attention and executive functioning (Sustained Attention-Dots). Participants self-reported on the extent to which they experienced psychological problems using the Symptom Checklist-90 (SCL-90). The SCL-90 total score (psychoneuroticism) was used as dependent variable in analyses of variance. Results: Frequent and current cannabis users performed more poorly than nonusers on the three tasks. They also reported more psychoneuroticism than nonusers whether they were classified according to their lifetime use, their use during the past 12 months, or use during the past 4 weeks. Moderate and former users did not differ from nonusers. Relatively poor performance on the Matching Facial Emotions task, as opposed to performance on the Face Recognition and Sustained Attention tasks, augmented levels of experienced psychoneuroticism among frequent and current cannabis users. Conclusions: Relatively poor cognitive abilities appear to represent increased vulnerability to effects of frequent and current cannabis use on affective mental health, even among highly educated individuals. There seems to be some specificity as to which (combinations of) neurocognitive abilities may be most indicative, as moderating effects were only observed when participants had relatively poor complex social perception ability.