Hundreds of millions of people worldwide have used cannabis at some point, making it the third most commonly used psychoactive substance after alcohol and tobacco.
Even William Shakespeare is thought to have experimented with the plant, after pipes unearthed at his home were found to contain cannabis residue. But while supporters often point to possible benefits, cannabis use can also come with drawbacks.
Beyond the familiar side effects like overindulging in snacks or dealing with cottonmouth, smoking cannabis has been linked to lung cancer risk, and use has also been associated with reduced fertility.
Some of these health impacts may take a long time to show up. However, one group faces a higher risk of more immediate, lasting consequences from using cannabis—whether that’s through bongs, edibles, or smoking a joint.
That group is people whose brains are still developing. Health educators ‘Talking With Docs’ addressed this in a video, including what they consider the ideal age to wait before using cannabis.
“There are three specific areas that are vulnerable to the effects of cannabis,” Dr Paul Zalzal and Dr Brad Weening said while discussing the neurological effects, outlining which parts of the brain they say can be affected when cannabis is used too early.
The doctor said: “That would be your prefrontal cortex, which is some of your decision making areas. Your hippocampus, where memories are made and consolidated, and your amygdala where your emotions are regulated.”
They added that although scientific knowledge about brain development has evolved, research has increasingly pointed to these regions being particularly sensitive, noting that ‘good studies’ show that ‘these areas are very vulnerable and are immature until age 25.’
This appears to align with multiple major studies and surveys published in recent years examining how cannabis use during adolescence and early adulthood can affect brain health and long-term wellbeing.
For example, a Columbia survey of 160,000 students in grades eight through 12, conducted between 2018 and 2022, reported that one in four had tried cannabis. It also found that students who used cannabis once or twice per month had double the risk of developing depression and anxiety.
Heavier cannabis use has also been tied to a higher likelihood of schizophrenia. Reviews of the research suggest cannabis may speed up the onset of the disorder and intensify symptoms, rather than being the sole cause in every case.
One important caveat raised in the research focuses on younger users. A study published in Psychological Medicine indicated that young men may face heightened risk, with male users reported to be four times more likely to develop schizophrenia than women.
The discussion isn’t meant to single out cannabis alone. A University of Colorado study reported that heavy alcohol use can have an even stronger effect on teenage brain development than cannabis, reducing gray and white matter and negatively affecting learning and information processing.
That same study also linked heavy teen cannabis use to ‘disrupted functional development, and decreased executive functioning and IQ,’ particularly among frequent users.
Unlike cannabis, which has annual overdose rate of zero and an almost-zero direct death rate in the general population, heavy alcohol usage driectly claims over 50,000 American lives each year.
Young people are also the group most likely to die directly due to alcohol use, with those aged 15 to 24 seeing a fatality rate around 66 percent higher than middle-aged adults.
Still, with a harm-reduction mindset, the YouTube doctors’ core message remains that anyone who is ‘determined’ to use cannabis should consider delaying until later in adulthood—specifically saying people should ‘wait until you’re 25 because the effects will be less.’