Marijuana today can be much stronger, a birthday experience shows

A writer's attempt to use cannabis on a milestone birthday led to an intense, disorienting reaction; experts note THC levels have risen from about 4% in the 1970s to more than 20% today and high-potency products are tied to increased risks including addiction and worsening mental health.

I tried legal cannabis on a milestone birthday after decades away from it and had an unexpectedly strong reaction. The visit included stopping at a Colorado dispensary and buying pre-rolled joints. At the time I did not realize how much average THC levels and available high-potency products have changed. Experts and studies cited in the article place those changes in the context of rising health concerns. Known findings: - Average THC levels in cannabis rose from about 4% in the 1970s to more than 20% today. - Cannabis concentrates can contain roughly 60% to 90% THC, and labeled potency may not always be accurate. - About 3 in 10 people who use today's more potent marijuana are reported to have cannabis use disorder. - Use of high-potency cannabis is associated with a roughly fourfold higher risk of addiction compared with lower-potency products. - Daily use of highly potent cannabis has been linked to a fourfold increase in risk of psychotic disorders in some studies. - SAMHSA and other sources report adolescent cannabis use can harm brain development and has been linked to lasting IQ losses. Summary: The personal episode illustrates how modern cannabis products can produce stronger and sometimes harmful effects compared with past decades, and researchers have documented links to addiction, mental health problems and increased emergency care visits. Ongoing research and monitoring continue as legal access expands; Undetermined at this time.