Drugs with psychedelic effects, like psilocybin, LSD, MDMA, and cannabis, may help protect the brain from some aspects of aging.

A recent survey of 3,294 US adults, aged between 42 and 92, has found that those who reported using a hallucinogen of any kind in the past year show fewer depressive symptoms and more favorable changes to their higher-order brain functions.

Compared to those who did not use psychedelics, those who did scored higher on tests conducted over the phone which assessed inductive reasoning, verbal fluency, working memory, processing speed, attention switching, and inhibitory control.

Psychedelic users did not, however, score better on episodic memory, which stores and retrieves everyday events and is often impacted by dementia.

The findings are only observational, so they can't determine cause and effect, and they rely on subjective accounts with uncontrolled drug doses. What's more, the study does not distinguish different types of psychedelics being taken.

Nevertheless, gerontologists Kallol Kumar Bhattacharyya from Utah State University and Kaeleigh Fearn from the University of South Florida think there's reason to keep exploring.

Psychedelics have recently garnered increasing scientific interest the world over, after several clinical trials found these drugs have the therapeutic potential to treat neuropsychiatric disorders, such as anxiety, depression, or post traumatic stress.

Some of the drugs identified with the most promising results include psilocybin (the active ingredient in magic mushrooms), LSD (Lysergic acid diethylamide), ketamine, and MDMA (3,4-Methyl​enedioxy​methamphetamine, commonly known as ecstasy).

Despite a growing number of clinical trials exploring the potential health benefits of these illicit and historically stigmatized drugs, today's studies rarely include older patients. In fact, the possibility that psychedelics could be used as a tool to restore processes in the aging brain has hardly been explored at all.

That's a significant oversight, argue Bhattacharyya and Fearn, as older adulthood is often associated with declines in executive function and mood disorders.

A number of recent studies on older cohorts suggest that psychedelics can enhance creativity and improve executive brain function, even at small doses.

"The federal and state governments should decriminalize psychedelics so that research can be conducted in a manner that ensures reliability and validity," the two researchers conclude.

"More longitudinal research, including clinical and community samples, is essential [to] utilizing psychedelics as an alternative therapy… in late-life cognitive functions."

Other scientists agree that we should start to consider psychedelic-assisted therapies for older adults. Rigorous, long-term trials will be needed to test the safety and efficacy of this approach before it could ever become an established clinical tool, of course.

Because some hallucinogens can impact the cardiovascular system, cause distressing 'bad trips', or pose risks for those with personality disorders, there is good reason to proceed with caution.

At the same time, cognitive decline and dementia are significant threats to aging humans around the world, and there are few treatments or therapies available to prevent them.

Further research on psychedelics could point drug researchers in the right direction, even if the substances don't turn out to be useful clinical tools in and of themselves.

For instance, Bhattacharyya and Fern suggest that maybe the reason psychedelics don't seem to have as much of an impact on episodic memory as they do on executive functioning is because "executive functioning is more hard-wired into the aging process".

Psilocybin, LSD, MDMA, and other psychedelics appear to stimulate new connections between neurons, and some might even repair broken connections. In initial clinical trials, these hallucinogens appeared useful in treating depression, as well as stress and anxiety disorders, all of which can be associated with mild cognitive impairment. Perhaps the drugs somehow relieve the brain of such emotional 'stress', allowing it to function better overall.

If psychedelics really do turn out to have enduring effects on mood and well-being, their controlled and carefully monitored use among older individuals in a therapy setting could be life changing.

The study was published in Gerontology and Geriatric Medicine.