Studies of the general population have not found that typical cannabis use clearly shortens life, but heavy use, daily use and cannabis use disorder are linked to higher death rates, especially from cardiovascular disease, suicide and injuries. The National Academies found the evidence on cannabis and overall mortality insufficient in 2017. Research since then points to risk concentrated among frequent and problem users rather than occasional ones.
This page previously summarized a 1997 Kaiser Permanente study of 65,171 Californians. That study remains one of the largest of its kind, but it measured use in the late 1970s and early 1980s, when products were far weaker. Below is what that study found and what newer research on cardiovascular death, heavy use and cannabis use disorder adds.
The Kaiser Permanente Study (1997)
Researchers at Kaiser Permanente in Northern California followed 65,171 health plan members aged 15 to 49 who answered questions about marijuana use between 1979 and 1985, with mortality tracked through 1991. Compared with nonusers and people who had tried it six or fewer times:
- Current marijuana use was not linked to a significantly higher risk of non-AIDS death in men.
- It was not linked to a higher risk of death from any cause in women.
- It was linked to higher AIDS mortality in men, which the authors concluded was most likely not caused by marijuana but by other differences between groups that the study could not measure.
The authors concluded marijuana use had little effect on non-AIDS mortality in men and on total mortality in women. The limits: participants were relatively young, follow-up ended in 1991, and cannabis at the time had much lower THC levels than today’s products.
What the National Academies Concluded
The National Academies of Sciences, Engineering, and Medicine’s 2017 report, a comprehensive review of cannabis health research, found no or insufficient evidence to support or refute a link between self-reported cannabis use and all-cause mortality. It reached the same conclusion for occupational accidents and injuries.
Newer Research on Cannabis and Death
Cardiovascular death
- The CARDIA study followed 5,113 young adults for a median 26.9 years and found no association between cannabis use and cardiovascular death by middle age. Most participants were light users.
- A 2024 analysis of 121,895 UK Biobank participants found heavy lifetime cannabis use was not significantly linked to death from any cause in men or women. In women, heavy use was linked to about 2.7 times the risk of cardiovascular death; in men, there was no such link.
- A 2025 meta-analysis in Heart pooling 24 studies found cannabis use was associated with about twice the risk of cardiovascular death, though with a wide margin of uncertainty.
Cannabis use disorder
The clearest mortality signal comes from people whose use has become a disorder. A 2025 Ontario study in JAMA Network Open followed people who needed emergency or hospital care for cannabis use disorder and compared them with matched members of the general population. Within five years, 3.5% had died versus 0.6% of the comparison group, an adjusted risk about 2.8 times higher. Risk was especially elevated for suicide, trauma, poisonings involving opioids or other drugs, and lung cancer. Their risk was still lower than that of people hospitalized for alcohol, stimulant or opioid problems.
That group is not typical of all users. But cannabis use disorder is common: the CDC estimates that about 3 in 10 people who use cannabis have it.
Mortality Studies at a Glance
| Study | Population | Main finding |
|---|---|---|
| Kaiser Permanente, 1997 | 65,171 adults 15 to 49 | No meaningful link to non-AIDS death in men or total death in women |
| CARDIA, 2017 | 5,113 adults, 27 years | No link with cardiovascular death |
| UK Biobank, 2024 | 121,895 adults | No significant link to all-cause death; higher cardiovascular death in women who were heavy users |
| Ontario, 2025 | People with hospital care for cannabis use disorder | About 2.8 times the five-year death risk of the general population |
| Heart meta-analysis, 2025 | 24 studies | About twice the risk of cardiovascular death |
The American Heart Association’s Position
The AHA’s 2020 scientific statement, “Medical Marijuana, Recreational Cannabis, and Cardiovascular Health”, found few cardiovascular benefits and many cardiovascular concerns, and it recommends against smoking or vaping cannabis. A 2024 study in the AHA’s journal linked daily cannabis use to higher odds of heart attack and stroke, the two leading cardiovascular causes of death. Read more in our cannabis and heart health guide.
Why Mortality Is Hard to Study
- Deaths are rare in young adults, who make up most cannabis users, so studies need huge samples and decades of follow-up.
- Use changes over time. A single survey answer may not reflect decades of habits.
- Confounding. Tobacco, alcohol, other drugs and mental health conditions affect death rates and are more common among heavy users.
- Potency has risen. Older studies measured exposure to much weaker cannabis.
Evidence at a Glance
| Claim | Evidence level | Source |
|---|---|---|
| Cannabis use raises overall death risk in the general population | Insufficient / mixed | National Academies 2017; Sidney 1997; UK Biobank 2024 |
| Cannabis use is linked to higher cardiovascular death | Limited to moderate (observational) | Storck 2025; UK Biobank 2024 |
| Cannabis use disorder is linked to higher death rates | Moderate (large cohort) | Myran 2025 |
| Cannabis use lengthens life | No evidence | National Academies 2017 |
Risks and Side Effects
- Impaired driving. Cannabis slows reaction time and coordination, and combining it with alcohol makes impairment worse, according to the CDC. Never drive high.
- Heart attack and stroke with frequent use. See cannabis and heart attack risk.
- Cannabis use disorder, which is linked to higher rates of suicide, injury and overdose involving other drugs.
- Lung damage from smoking. See our cannabis and asthma guide.
Talk to Your Doctor
Tell your doctor if you use cannabis, especially if you use daily, have heart disease, also smoke tobacco, or have depression or other mental health conditions. Signs that use may be becoming a disorder include needing more to get the same effect, failed attempts to cut back, and use getting in the way of work, school or relationships. Treatment helps, and the SAMHSA National Helpline (1-800-662-4357) is free and confidential. If you or someone you know is in crisis or thinking about suicide, call or text 988.
Explore more in our cannabis research section, or read the legal basics in our cannabis laws hub.
Cannabis and Mortality FAQ
Does smoking weed shorten your life?
For typical users, studies have not shown a clear effect on overall lifespan. Heavy use and cannabis use disorder are linked to higher death rates, particularly from cardiovascular disease, suicide and injuries.
Can you die from a marijuana overdose?
Deaths directly from cannabis poisoning are not what the large mortality studies identify as the main risk. The deaths linked to cannabis come mostly from accidents, heart events, suicide and other drugs, and very high doses can cause severe symptoms that need emergency care.
Is daily cannabis use linked to early death?
Daily use is linked to higher odds of heart attack and stroke, and heavy use was linked to higher cardiovascular death in women in the UK Biobank. Direct evidence on overall lifespan is still limited.
What did the Kaiser Permanente marijuana mortality study find?
Among 65,171 adults, marijuana use had little effect on non-AIDS deaths in men or total deaths in women. A link with AIDS deaths in men was judged to reflect other factors, not marijuana itself.
Is cannabis safer than alcohol for mortality?
In the 2025 Ontario study, people hospitalized for alcohol problems had a higher five-year death risk than those hospitalized for cannabis use disorder. That compares people with serious problems, not typical users.
For adults 21+ in legal states. General information, not medical advice. Talk to a doctor before using cannabis for a health condition.