Looking for interactions Towards a more complete neurocognitive model of cannabis use and cannabis use disorder

This thesis explores the complex nature of cannabis use, considering factors that influence initiation, escalation towards heavy use, and the potential development of a cannabis use disorder (CUD). Literature reviews show that cannabis intoxication impairs learning, memory, attention, and motor inhibition, but the long-term effects are less clear with heavy use and CUD only consistently being associated with impairments in learning and memory. Investigation of the potential use of hair-derived cannabinoid concentrations to detect cannabis use revealed that THC can be detected in hair samples but isn't strongly associated with self-reported use or problems. CUD symptoms appear to be differentially associated with the presence of comorbid psychiatric disorders in men and women, but no sex differences in cognitive control-related brain processes during working memory tasks were observed. An attentional bias towards cannabis cues was only observed in those in treatment for CUD, but craving appeared to moderate the association between attentional bias and cannabis use in occasional to regular cannabis users. Furthermore, cannabis related cues affected cognitive control related brain activity during a working memory task in cannabis users specifically. Cultural attitudes towards cannabis moderated the association between measures of cannabis use and resting state functional connectivity in substance use disorder related brain networks as well as cognitive control related brain activity during a working memory task. Assessment of the effect of the COVID-19 lockdown showed an increase in cannabis use, but not CUD severity in regular cannabis users. Additionally, the newly developed social attunement questionnaire – assessing the tendency to harmonize with the social environment – is validated and the potential role of social attunement in substance use is explored. In sum, this thesis emphasizes the need to consider individual variations and interactions between various factors in understanding cannabis use and CUD, serving as a foundation for a more comprehensive neurocognitive model of cannabis use and CUD and proposing a cannabis research checklist guiding future studies.