Cannabis and Aging
Condition: Cannabis Use
MeSH terms: Marijuana Abuse
Study type: Observational

Summary: 
      With increased availability and use of cannabis by older adults aged ≥ 50 years, a rigorous
      evaluation of the benefits and risks of cannabis use in these individuals is necessary. Our
      proposed project will investigate whether older adults who initiate cannabis use after the
      age of 50 are at an increased risk of fall and what are the underlying mechanisms. We will
      measure motor and cognitive function in older cannabis users and nonusers and we will use
      positron emission tomography to determine brain activity and how it is associated with fall
      risk.
    

Detailed description: 
      The prevalence of cannabis use has increased significantly in recent years among US adults
      aged 50 years and older. With increased availability and use of cannabis by older adults, a
      rigorous evaluation of the benefits and risks of cannabis use in these individuals is
      necessary. Aging is characterized by physiological and social changes that make older adults
      vulnerable to chronic disease and geriatric conditions, including cognitive impairment and
      falls. Unintentional falls are a common event for older adults and a major cause of morbidity
      and mortality linked with a decline in functional status and disability. Moreover, falls and
      cognitive impairment are a "well-known couple"; as older adults with moderate to severe
      cognitive impairment have a higher risk of falls, with an annual incidence of around 60-80%,
      which is twice the rate of cognitively normal older adults. Impaired cognitive function is an
      effect of cannabis use, and there is increasing evidence that those effects may persist later
      in life. Therefore, the physiological effects of chronic cannabis use may further increase
      falls in older adults via alterations in gait and cognition. Studies have shown reduced
      neural activity in the frontal brain networks and associations with increased fear of falling
      in older adults. It is also known that in regular cannabis users, the effects of cannabis may
      have an impact on cognitive-motor skills and brain mechanisms that modulate coordinated
      movement. The goal of this application is to investigate the neural correlates of fall risk
      and cognitive and motor function in individuals who initiate drug use after the age of 50. We
      will use FDG-PET to determine brain activity. Fall risk and cognitive/motor function will be
      assessed with the measures from the NIH Toolbox and a fall risk model. Our central hypothesis
      is that older chronic cannabis users are at a higher fall risk than older non-users, which is
      associated with reduced cerebral FDG uptake. These results are expected to provide critical
      and timely data to the public and health professionals regarding the effects of self-directed
      cannabis use on increased fall risk and if clinicians need to assess cannabis use when
      determining fall risk and deciding prevention strategies.
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        A total of 30 older (age 50-80 years) men and women who are using cannabis and 30 controls
        who are non-users, will be recruited.
      
Keywords: Cannabis; Aging; Falls; Brain Glucose Uptake