“People in their 80s and 90s, even retired Air Force colonels, are finding such relief” with cannabis, said Ms. Horne. “Almost everybody I know is using it in one form or another” — including her husband Hal, 68, a retired insurance broker, who says it helps him sleep.

In fact, so many Laguna Woods seniors use medical cannabis — for ailments ranging from arthritis and diabetes nerve pain to back injuries and insomnia — that the local dispensary, Bud and Bloom, charters a free bus to bring residents to its Santa Ana location to stock up on supplies. Along with a catered lunch, the bus riders get a seniors discount.

Physicians who treat older adults expect their cannabis use to increase as the number of states legalizing medical marijuana keeps growing…

“You might not like it,” Dr. David Casarett, chief of palliative care at Duke University Medical Center, tells fellow physicians. “You might not believe in it. But your patients are using this stuff.”