Association between wildfire smoke exposure and parents' adoption of protective behaviours: Exploring the role of objective and subjective smoke exposure.

Use and acceptance of medical and recreational cannabis have expanded in the United States, alongside increased legalization at the state level [, ]. Cannabis use is most common among young adults (age 18-25), with 24.1% reporting use in the past month and 14.4% meeting diagnostic criteria for cannabis use disorder in 2021 [], raising concerns about possible harm, including impacts on cognitive functioning []. At the same time, public perception of harm related to cannabis use has decreased [], and there is evidence that cannabis can be beneficial for managing pain, sleep issues, and stress [-]. Furthermore, several different compounds in cannabis, including tetrahydrocannabinol (THC) and cannabidiol (CBD), are recognized as having anti-inflammatory properties which may be beneficial [, ]. In this complex context, study outcomes are influenced by individual differences in motivation for use, variation in product properties (e.g., content of THC, CBD), and route of administration, as well as use characteristics such as frequency. It is critical to better understand the potential consequences of use, particularly within specific populations that may be more susceptible to negative or positive cognitive impacts. Given these complexities, we examined the impact of cannabis use frequency on cognitive performance in young adults, some living with HIV infection, to improve understanding of the potential benefits of cannabis among young individuals living with a chronic neuroinflammatory disease. These data may instruct future studies addressing tailored guidelines for cannabis use among populations experiencing neuroinflammation. Research on the cognitive effects of chronic cannabis use in adolescents and young adults, i.e. differences observed outside the period of acute intoxication, has reported negative impacts across cognitive domains including learning and memory, attention, processing speed and executive functions [, -]. Dellazizzo and colleagues, in a review of studies of adolescents and adults [], noted that verbal, but not visual, learning and memory and executive functions were the cognitive domains most consistently demonstrating negative effects of cannabis use, while attention and processing speed outcomes were more variable. Recent studies and reviews document poorer performance associated with frequent or heavy use in learning, attention, executive functions, memory and processing speed [, , , -]. Frolli and colleagues [] specifically showed a dose-dependent relationship with heavy chronic users showing significantly worse performance in working memory, processing speed, IQ and visuospatial reasoning relative to occasional or non-users. Overall, heavy use appears to have negative consequences on learning and memory, executive functions, and processing speed, although there are suggestions that mild or moderate use may have fewer consequences. Given the influence cannabis use has on neuroinflammatory pathways [], there is potential for some positive impacts on brain health for people living with HIV infection (PWH). Even in the current era of effective systemic viral suppression with antiretroviral medications, HIV affects central nervous system (CNS) functioning in up to 40% of individuals and has the potential to disrupt CNS development []. Cognitive effects of HIV are most commonly observed in domains considered to represent more “fluid cognition”, including episodic and working memory, executive functions, and processing and psychomotor speed [-]. The ongoing impact of HIV on the CNS is hypothesized to be mediated by gut dysbiosis and immune activation, established early in infection, and resulting chronic neuroinflammatory processes [, -], including the release of inflammatory cytokines [, ], that contribute to cognitive deficits. Plasma markers of immune activation and cytokines (e.g., sCD163, interleukin-6) are elevated in HIV and associated with neurocognitive dysfunction in adults [] and youth [].