Surprising Side Effects of Marijuana After 50

The statistics are surprising: More and more older people are smoking pot, that drug stereotypically associated with disaffected youth. A 2018 review of studies found that the greatest increase in American marijuana use was in people over 50. And according to a study published in the International Journal of Drug Policy, marijuana use in people over 65 increased by 75 percent between 2015 and 2018. Those studies also indicate that older people consider marijuana use relatively harmless. But pot can affect people over 50 differently than younger people, sometimes in unexpected ways.

Older people who use marijuana are more likely to be stressed or depressed than non-users, and the rate of depression between 2006 and 2013 in that age group increased 100%, according to the review of studies published in the journal Gerontology and Geriatric Medicine. This could be because some marijuana users are self-medicating with the drug instead of seeking professional help. But because pot directly affects the brain, it can complicate mental health conditions or interfere with treatment. 

"Marijuana use can cause cognitive impairment and should be used with caution if you have a mental health condition," warns the Mayo Clinic. "Marijuana use might worsen manic symptoms in people who have bipolar disorder. If used frequently, marijuana might increase the risk of depression or worsen depression symptoms." If you're taking SSRIs for depression, mixing them with marijuana may increase the chance of mania. 

Research published last winter on JAMA Network Open found an association between the use of cannabinoids containing THC (the active ingredient in marijuana) and thinking and perception disorders in people over 50. "Self-reported thinking or perception disorders reflect alterations in thinking and perception typically described under psychotic symptoms," the authors wrote, although they described these findings as "tentative."

Not to sound like Reefer Madness, we're just passing this along: a 2017 study found that marijuana users 50 to 64 years old were more likely to participate in risky activities, including driving under the influence, theft, and physical violence, compared to older nonusers. Other studies have found that marijuana users 65 years or older were more likely to drive under the influence compared to older adults who don't use pot.

According to the Mayo Clinic, marijuana can cause side effects when mixed with other medications. These include increasing the risk of bleeding, lowering blood pressure, reducing the effects of antivirals, increasing the sedative effects of certain drugs, and affecting blood sugar levels. That may make marijuana use riskier for people taking anticoagulants or medications for chronic conditions like high blood pressure, HIV, and diabetes.

Marijuana can cause drowsiness, dizziness, and disorientation, risky in any age group but particularly dangerous in older adults, increasing the risk of falling, a 2014 study found. A later study also found that marijuana use has been associated with injury in older adults, along with visits to the emergency department.

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Marijuana is known to increase appetite; "the munchies" are a well-known side effect. (Marijuana is also prescribed medically to cancer and HIV patients who have lost their appetite.) While the munchies may be relatively harmless when you're younger, in older people, the side effects can be dangerous, especially if you're at an unhealthy weight or have diabetes or heart disease (the risk of which increases with age). 

Several studies have found that found marijuana users self-reported a higher intake of alcohol, sodium, pork, cheese, and salty snacks but fewer fruits and vegetables than nonusers. "The stimulation of appetite … could be life-threatening for someone with diseases such as diabetes and cardiovascular disease, where a healthy diet may be vital to improved health outcomes," wrote the authors of the review of studies published in Gerontology and Geriatric Medicine.