Long-Term Recreational Cannabis Use Is Associated With Lower Executive Function and Processing Speed in a Pilot Sample of Older Adults.

Abstract

More older adults are using cannabis for recreational and/or medical purposes, but most studies examining cognitive function and cannabis use do not include older adults. The current small pilot study sought to compare cognitive function and emotional functioning among adults age 60 and older who were regular, primarily recreational cannabis users (n = 28) and nonusers (n = 10). A bimodal distribution was observed among cannabis users such that they had either initiated regular use more recently ("short-term" users; ≤7 years, n = 13) or earlier in life ("long-term" users; ≥19 years, n = 15). Nonusers, short-term, and long-term users were not different in depression, anxiety, or emotion regulation, or alcohol use. Nonusers scored significantly higher than long-term users in executive function. Short-term users scored significantly higher than long-term users in executive function, processing speed, and general cognition. Additionally, greater recent cannabis use frequency was negatively associated with working memory. The current findings suggest that short-term recreational cannabis use does not result in differences in cognitive performance compared to nonusers, which may indicate that short-term use is relatively benign in older adults. However, longer duration of use is associated with poorer processing speed and executive functioning, and more recent cannabis use is associated with poorer working memory, which may impact older adults' overall cognitive functioning.