Can Psychedelics Help Maintain Thinking Skills and Lower Depression as We Age?

Senior woman, celebrating her birthday, 85 years old, in a garden.
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Rates of dementia and other cognitive (thinking) disorders, along with aging-related chronic conditions, are expected to significantly increase in coming years, due to ever greater numbers of older people. Rates of depression may also increase, as it is sometimes an early symptom of dementia, and because living with age-related illnesses can sometimes be an emotional burden. Dementia and depression currently have no cure, and available drug treatments can come with significant side-effects. Psychedelic therapy, however, has shown positive impacts on both cognition and mental health issues, without long-lasting negative effects.

Research has shown that psychedelics (non-addictive, hallucinogenic substances such as psilocybin, LSD, mescaline, and cannabis) may be useful in treating mental health and cognitive disorders because of their effects on the brain. Psychedelics can stimulate the growth of neurons (a type of brain cell), which are important for learning and memory. They produce changes in neuroplasticity, which affects how well the brain adapts and how well the brain’s neurons communicate. They also lower inflammation in the brain, high levels of which are associated with developing Alzheimer’s.

This study looked at whether the use of psychedelics improved cognitive function and reduced depression in older adults. Researchers looked at data on 2500 participants in MIDUS 3, aged 42 to 92 years, including:

    • Psychedelic use: whether in the past year participants reported using marijuana, LSD, or other hallucinogens (such as PCP, Angel dust, Peyote, Ecstasy (MDMA), Mescaline, Prozac).
    • Cognitive function: was tested over the phone, including measurements of:
        • executive function- our ability to pay attention, learn, plan, manage our daily lives, and control our emotions, measured by tasks such as counting backward and completing the pattern in a series of numbers
        • episodic memory- our long-term memory that allows us to store information about the important events in our lives, measured by recalling 15 items
    • Depression: whether or not participants had depressive symptoms, such as losing interest in most things, that persisted for two or more weeks in the past 12 months.

Results showed that psychedelic use was significantly associated with better executive function (but not episodic memory) and fewer depressive symptoms, after controlling for variables such as age, education, employment, and chronic conditions.

 Due to the expected increase in rates of dementia and other mental and physical health problems among older adults in coming years, these results indicate that psychedelic therapy warrants more research into its potential to help with these problems. Other studies have shown that psilocybin and LSD are useful in treating mental health disorders, which is significant because depression is often associated with cognitive problems and dementia. One study showed that a single dose of psilocybin reduced depressive symptoms even after 6 weeks, with no ill effects. This is compared to anti-depressant medications whose side effects can include diarrhea, constipation, abdominal pain, insomnia, anxiety, and headaches. Older adults, due to age-related biological changes, can experience even more serious side effects, including reduced appetite, confusion, agitation, and psychosis.

Psychedelics have been used by humans for thousands of years and in many cultures and religions. Such extensive use suggests that they likely have positive benefits. Currently, though, they are illegal in the United States and lack research funding. This is possibly a reaction against “hippies” in the 1960s protesting the Vietnam War. Their use of psychedelics became associated with youth rejecting social norms. Such drugs were outlawed by federal law in 1970. Nonetheless, the recreational use of psychedelics has increased since then. Psychedelic therapy for treating mental health disorders, which involves taking hallucinogens in a controlled therapeutic setting overseen by mental health professionals, is also gaining in popularity.

Future research would benefit from use of larger sample sizes, since only 8.2% of MIDUS participants reported using psychedelics. More detail about the exact dosing used by participants, and longitudinal data looking at how psychedelic use affects cognition and depression over time, is also needed. Research into micro-dosing (taking small, recurring doses that do not alter perception) of psilocybin or LSD may be beneficial for those who want to avoid the hallucinogenic effects.

 Source: Fearn, K., & Bhattacharyya, K. K. (2024). Is use of psychedelic drugs a risk or protective factor for late-life cognitive decline? Gerontology and Geriatric Medicine, 10, 1-9. https://doi.org/10.1177/23337214241250108

Read the full article at: http://www.midus.wisc.edu/findings/pdfs/2858.pdf