A longitudinal study of cannabis use and risk for cognitive and functional decline among older adults with HIV
C. Watson, E. Sundermann, J. Helm, Emily W. Paolillo, Su-Zi Hong, Ronald J Ellis, Scott Letendre, T. Marcotte, Robert K Heaton, E. Morgan, Igor Grant
AIDS and behavior May 8, 2023 DOI: 10.1007/s10461-023-04056-6 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Longitudinal Peer reviewed |
|---|---|
| Sample size | 297 |
| Population | Older adults with HIV, ages 50-84 at baseline |
| Duration | Up to 10 years (average 3.9 years of follow-up) |
| Topics | Cannabis |
| Key findings | Occasional cannabis use (weekly or less) was associated with better global cognition over time compared with no use, while frequent use showed no such association. Rates of cognitive decline and functional problems did not differ by average cannabis use. Recent THC exposure, measured by positive urine toxicology, was linked to temporarily worse memory at those visits, without reported functional decline. |
Abstract
Cannabis use is rapidly increasing among older adults in the United States, in part to treat symptoms of common health conditions (e.g., chronic pain, sleep problems). Longitudinal studies of cannabis use and cognitive decline in aging populations living with chronic disease are lacking. We examined different levels of cannabis use and cognitive and everyday function over time among 297 older adults with HIV (ages 50–84 at baseline). Participants were classified based on average cannabis use: frequent (> weekly) ( n = 23), occasional (≤ weekly) ( n = 83), and non-cannabis users ( n =191) and were followed longitudinally for up to 10 years (average years of follow-up = 3.9). Multi-level models examined the effects of average and recent cannabis use on global cognition, global cognitive decline, and functional independence. Occasional cannabis users showed better global cognitive performance overall compared to non-cannabis users. Rates of cognitive decline and functional problems did not vary by average cannabis use. Recent cannabis use was linked to worse cognition at study visits when participants had THC+ urine toxicology—this short-term decrement in cognition was driven by worse memory and did not extend to reports of functional declines. Occasional (≤ weekly) cannabis use was associated with better global cognition over time in older adults with HIV, a group vulnerable to chronic inflammation and cognitive impairment. Recent THC exposure may have a temporary adverse impact on memory. To inform safe and efficacious medical cannabis use, the effects of specific cannabinoid doses on cognition and biological mechanisms must be investigated in older adults. El consumo de cannabis está aumentando rápidamente entre los adultos mayores en los Estados Unidos, en parte para tratar síntomas de afecciones de salud comunes (p. ej. dolor crónico, problemas de dormir). Actualmente, hay pocos estudios longitudinales sobre el consumo de cannabis y el deterioro cognitivo en poblaciones que envejecen y viven con enfermedades crónicas. Examinamos diferentes niveles del consumo de cannabis y funciones cognitivas a lo largo del tiempo entre 297 adultos mayores con VIH (de 50 a 84 años al principio de la investigación). Los participantes se clasificaron según el consumo promedio de cannabis: consumidores de cannabis frecuentes (> semanal) ( n = 23) ocasionales (≤ semanal) ( n = 83), y no consumidores de cannabis ( n =191) fueron seguidos longitudinalmente hasta por 10 años (promedio = 3,9 años). Los modelos multinivel investigaron los efectos del consumo promedio y reciente de cannabis en la cognición global, el deterioro cognitivo global, y la independencia funcional. Los consumidores ocasionales de cannabis mostraron un mejor rendimiento cognitivo global en comparación con los no consumidores. El nivel de deterioro cognitivo y problemas funcionales no estuvieron asociado con el uso de cannabis. El consumo reciente de cannabis se vinculó con una peor cognición en las visitas del estudio cuando los participantes tenían toxicología de orina de THC positivo–esta disminución a corto plazo de la cognición se debió a una peor memoria, pero no se extendió a los informes de deterioros funcionales. El consumo ocasional (≤ semanal) de cannabis se asoció con una mejor cognición global a lo largo del tiempo en adultos mayores con VIH, un grupo susceptible a la inflamación crónica y la disfunción cognitiva. La exposición reciente al THC puede tener un impacto negativo temporal en la memoria. Los efectos de dosis específicas de cannabinoides en la cognición y sus mecanismos de acción biológicos deben ser investigados en personas mayores con el fin de informar el uso seguro y eficaz del cannabis medicinal.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cited by 2
- THC induced similar physiological effects on HIV transgenic rats and their controls without affecting HIV-induced deficits in effortful motivation. Journal of Cannabis Research January 2, 2026
- Beneficial and adverse effects of THC on cognition in the HIV-1 transgenic rat model: Importance of exploring task- and sex-dependent outcomes. Brain, Behavior, and Immunity April 1, 2025
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