Older generation 'going to pot'
More older people in the US are using marijuana as a recreational drug, figures have shown.
The number of people aged 50 and older reporting marijuana use increased from 1.9% to 2.9% from 2002 to 2008, according to surveys from the Substance Abuse and Mental Health Services Administration.
The rise was most dramatic among 55 to 59-year-olds, whose reported use more than tripled from 1.6% in 2002 to 5.1%.
Observers expect further increases as 78 million baby boomers born between 1945 and 1964 get older.
Politically, advocates for legalising marijuana say the number of older users could represent an important shift in their decades-long push to change US laws.
"For the longest time, our political opponents were older Americans who were not familiar with marijuana and had lived through the 'Reefer Madness' mentality and they considered marijuana a very dangerous drug," said Keith Stroup, the founder and lawyer of NORML, a marijuana advocacy group.
"Now, whether they resume the habit of smoking or whether they simply understand that it's no big deal and that it shouldn't be a crime, in large numbers they're on our side of the issue."
The drug is credited with relieving many problems of ageing: aches and pains, glaucoma, macular degeneration, and others. Patients in 14 states enjoy medical marijuana laws, but those elsewhere buy or grow the drug illegally to ease their conditions.
But older users could be at risk for falls if they become dizzy, and smoking marijuana increases the risk of heart disease and can cause cognitive impairment, said Dr. William Dale, chief of geriatrics and palliative medicine at the University of Chicago Medical Centre.
"There are other better ways to achieve the same effects," he said.