Studies Examine Effects of Cannabis Use on Brain Function
Multiple studies have examined the effects of cannabis use on brain function, with findings varying significantly by age group and individual usage patterns.
Research on Young Adults
A study from the University of Colorado Anschutz examined adults aged 22 to 36 with varying levels of cannabis consumption. Researchers categorized usage as follows:
- Heavy use: Over 1,000 lifetime uses.
- Moderate use: 10 to 1,000 lifetime uses.
- Non-use: Below 10 lifetime uses.
63% of heavy users and 68% of recent users showed reduced brain activity during working memory tasks.
Researchers gave over 1,000 participants seven cognitive tasks while scanning their brains. The observed reduced activity appeared to affect areas of the brain involved in decision-making, memory, attention, and emotional processing.
Assistant professor Joshua Gowin stated that people should be aware of their relationship with cannabis, noting that abstaining suddenly could disrupt cognition. He emphasized that large, long-term studies are needed to understand whether cannabis directly changes brain function, how long effects last, and the impacts on different age groups.
Additional Findings on Cognitive and Brain Health
Other research has highlighted specific concerns regarding brain physiology and memory function in cannabis users.
Dr. Daniel Amen, who has conducted extensive brain scans, stated that cannabis users demonstrate widespread reductions in cerebral blood flow, particularly in regions critical for memory, coordination, emotion, and executive function. He warned that long-term use could negatively impact mental health, with brain imaging showing decreased amygdala activity that could lead to emotional blunting and increased rates of anxiety, paranoia, and psychosis.
A Washington State University study found that THC increases susceptibility to false memories and impacts verbal memory, visuospatial memory, prospective memory, source memory, and temporal order memory.
Associate professor Carrie Cuttler explained that THC hijacks memory pathways, but noted that abstaining for a month could lead to a complete rebound and that alcohol's impact on memory is worse.
Contrasting Research on Older Adults
A separate University of Colorado study analyzed data from over 26,000 cannabis users in the UK, focusing on older adults. Lead author Anika Guha noted that more older adults are using cannabis for different reasons than younger people, such as for sleep and chronic pain.
The study found that among older adults, more lifetime cannabis use was generally associated with larger brain volumes and better cognitive function.
"This is not a case of cannabis being all good or all bad," Guha explained. "Effects depend on usage patterns and THC content."
Guha also pointed out an important caveat: many study participants had historical cannabis usage from when cannabis was significantly less potent than what is commonly available today.
For Further Information
The article included contact information for FRANK, a confidential drug advice service. They can be reached:
- By phone: 0300 123 6600
- By text: 82111
- Via their website, available 24/7
- Via livechat from 2pm to 6pm daily