Synthetic marijuana and brighter lights could help improve the lives of people with dementia, according to new research presented Tuesday at the Alzheimer’s Association International Conference in Chicago.

Alzheimer’s disease and related dementias are best known for causing a breakdown in cognitive abilities. But a host of other symptoms — including agitation, anxiety, depression and insomnia — reduce patients’ quality of life, create more challenges for caregivers, and are the leading causes for placement in assisted-living facilities or nursing homes.

The Food and Drug Administration has not approved any drug treatments for these symptoms, although some pharmaceuticals, such as antipsychotics, approved for other diseases are prescribed off-label for Alzheimer’s patients. However, they are associated with increased apathy, strokes and deaths.

But a synthetic form of tetrahydrocannabinol (THC), the active chemical in marijuana, was found to be safe and effective in treating agitation, lack of appetite and other behavioral symptoms in dementia patients, according to a new study out of the University of Toronto.

In the trial, 39 people with moderate to severe Alzheimer’s dementia received nabilone, a synthetic form of THC that is easier to regulate and is available in capsule form, for six weeks and a placebo for six weeks. While on nabilone, their agitation levels and neuropsychiatric symptoms were reduced while their appetites improved, as exhibited in clinical tests and caregiver reports.

“We’re excited because we think this opens a whole new door for cannabinoids as a group for treating agitation in Alzheimer’s disease,” said Krista Lanctot, a professor of psychiatry and pharmacology-toxicology at the University of Toronto.

The capsules are approved to treat the nausea and vomiting associated with chemotherapy; this is the first clinical trial in which they were given to Alzheimer’s patients, Lanctot said.

Similar to recreational marijuana, the synthetic version reduces pain and anxiety and increases appetite. The “fuzzy brain” associated with recreational use is not a concern with Alzheimer’s patients because they already have memory problems, Lanctot said. And the synthetic form, which is modified to be less potent, can also have effects that prevent neurons from dying, she said.

Lanctot said she hopes to get funding for a bigger trial; a 10-person trial of another synthetic cannabinoid is starting in the United States.

In the meantime, she cautioned people not to confuse the synthetic drug with the other kind. “We don’t want someone going out and giving Grandma marijuana because they think it’s going to help,” she said.

Also Tuesday, scientists from the Lighting Research Center at Rensselaer Polytechnic Institute presented findings on a lighting system tailored to improve sleep, mood and behavior for nursing-home residents with Alzheimer’s and related dementias.

Researchers provided nursing-home residents with bright, blue-white light during the day and dimmer, yellow-white light in the evening to better mimic the body’s circadian rhythms. Forty-three residents participated in a four-week study and 37 in a six-month study. Both used a custom-designed LED light table or individual room lighting, and personal meters measured the light exposure received by patients’ eyes. Sleep disturbance, mood and agitation were also measured and were found to be eased in both groups during the lighting intervention.

The findings could make facilities rethink their lighting design. Most nursing homes have “horrible, very low, continuous dim light” that doesn’t change during the day, said Mariana Figueiro, the center’s director. Such lighting negatively affects the body’s production of melatonin, which helps people sleep.

The standards at most facilities are based on people’s ability to see, which is different from the amount of light needed for their biological clocks, Figueiro said, adding that low light also saves energy. But many facilities are turning to energy-efficient LEDs, whose color and intensity are easier to regulate than those of incandescent or fluorescent lights.