Researchers from the University of California at San Diego examined the long-term impact of cannabis use on cognition among 297 older adults with HIV. The study ultimately found that those participants with a history of occasional cannabis consumption displayed a greater cognitive performance than those who don’t use cannabis at all.
The findings were published in the journal AIDS and Behavior.
Cannabis, Cognition and HIV: An Understudied Issue
Researchers noted the prevalence of cannabis as a treatment for common health conditions while nodding to the lack of studies regarding cannabis use and cognitive decline, specifically among aging populations.
Participants consisted of frequent cannabis consumers who used cannabis multiple times per week, occasional consumers who used cannabis once per week or less, and non-users. Researchers assessed the cognition of participants for up to 10 years to examine the effects of average and recent cannabis use on global cognition, global cognitive decline, and functional independence.
Ultimately, the study authors determined that participants with a history of occasional cannabis use performed the best out of the three groups.
“In a longitudinal, well-characterized cohort of older adults with HIV, we found that occasional cannabis use in later-life was associated with better overall global cognition compared to no cannabis use, a potentially important finding given this population’s increased vulnerability to cognitive impairment,” researchers stated.
“Further, frequent cannabis use did not relate to worse global cognition over study follow-up, … suggesting that cannabis use within the ranges observed in this study is not a risk factor for early decline in any cognitive domain.”
‘No Evidence’ That Cannabis Use Influences Cognitive Decline
Researchers also recognized that frequent cannabis use was not associated with a decline in cognitive performance throughout the study period. Specifically, they noted that “rates of cognitive decline and functional problems did not vary by average cannabis use.”
Researchers did note that recent cannabis use specifically was linked to worse cognition at study visits, when participants had THC-positive urine toxicology. However, this short-term decline in cognition was driven by worse memory and did not extend to reports of functional declines, according to the study.
In the study conclusion, researchers noted that the study is the first to their knowledge to characterize longitudinal patterns of current cannabis use and global cognitive performance over time among older adults with HIV.
“We found no evidence that cannabis use influences risk for cognitive nor functional decline,” researchers stated. “Further mechanistic work is needed to probe this positive finding to inform whether cannabinoids show therapeutic potential in treating chronically elevated neuroinflammation and reducing downstream cognitive problems in people with HIV.”
Adding to the Literature and Looking Ahead
The effect cannabis has on cognition in general is not a new research topic, though it can be a bit complex to approach. One study similarly noted that cognitive effects typically depend on frequency of use and duration of time since last exposure to cannabis. Specifically, it found that working memory is significantly impaired following acute cannabis exposure, though these deficits resolve with sustained abstinence.
“The long-term effects of cannabis on executive function is most clearly demonstrated when studies use chronic, heavy cannabis users, as opposed to light, occasional users,” researchers said.
Though, examining the relationship between cannabis and adults with HIV is surely a subject worth looking into, given that up to one-third of HIV-positive individuals have reported using cannabis to treat symptoms. Other studies have suggested that cannabis may provide “a beneficial intervention to reduce morbidity related to inflammation” and a “novel means to reduce morbidity and mortality” in people living with HIV.
Looking ahead, researchers said that “the effects of specific cannabinoid doses on cognition and biological mechanisms must be investigated in older adults” in order to inform safe and effective medical cannabis use.