As marijuana becomes more accepted globally for medical and recreational use, many adults continue using it into their 30s.

However, recent research raises concerns about the long-term effects of cannabis use beyond age 30.

A study conducted by The University of Queensland in Australia indicates that continuing to smoke weed into your 30s might negatively impact several important life areas.

The Long-Term Effects of Marijuana Use in Adulthood

In recent years, cannabis use has gained widespread acceptance, with many countries and states legalizing its recreational and medicinal use. While marijuana is often considered a relatively harmless substance, emerging research suggests that long-term use—especially into adulthood—may carry significant risks. If you are still using cannabis regularly at 30, scientists have identified potential negative effects that warrant consideration.

Cognitive Decline and Brain Function

One of the primary concerns regarding prolonged marijuana use is its impact on cognitive function. Studies indicate that chronic cannabis consumption can lead to declines in memory, attention, and processing speed. The brain continues to develop well into a person’s mid-20s, and extended cannabis exposure may contribute to structural and functional changes in key areas such as the prefrontal cortex, which is responsible for decision-making and impulse control.

A longitudinal study published in JAMA Psychiatry found that individuals who used cannabis heavily into adulthood exhibited reduced IQ scores and impaired cognitive abilities compared to non-users. These effects were more pronounced in individuals who started using marijuana in adolescence and continued through adulthood.

Mental Health Risks

Scientists have also linked prolonged cannabis use to an increased risk of mental health issues. Regular marijuana consumption has been associated with heightened rates of anxiety, depression, and psychotic disorders, particularly in individuals with a genetic predisposition to mental illness.

A study from The Lancet Psychiatry highlighted that daily cannabis users, especially those consuming high-potency strains, are at a significantly greater risk of developing psychosis compared to non-users. Chronic use can also lead to Cannabis Use Disorder (CUD), a condition characterized by dependence, withdrawal symptoms, and difficulty in controlling usage.