The effects of THC in marijuana

DENVER (AP):

There are hundreds of strains of marijuana each containing hundreds of different chemicals but only one molecule makes much difference, scientists say.

It's all about the THC.

Purveyors and boosters of marijuana or cannabis whether recreational or medicinal, counterclaim that the experience varies to great effect among all the amazing varieties cultivated over thousands of years.

Almost five millennia after the Chinese used medicinal cannabis, Colorado voters approved it in 2000, and they did the same for adult recreational use in 2012.

A majority of the state's voters have decreed cannabis is good medicine and good fun, but they might not know what the drug is doing to the body.

When a person smokes, inhales or ingests marijuana or pot the green, brown or grayish dried and shredded leaves, stems, flowering buds or seeds of plants called cannabis sativa or cannabis indica more than 200 different chemical compounds course through the body. About 60 of them are called cannabinoids.

"Everybody likes something different," said Ean Seeb, co-owner of the Denver Relief Medical Marijuana Dispensary. "They can now pick what really works for them."

Yet after 75 years of scientific research, it has been found the concentration of the psychoactive compound, THC, is what really matters, said psychopharmacologist Kari Franson, an associate dean and professor with the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences.

healthy volunteers

Franson worked at an institute that studied the effects of cannabinoids in healthy volunteers in the Netherlands, where it was easier to do research on it than in the United States.

"You can study, study, study it, but it's THC (Delta-9-tetrahydrocannabinol) that is the active ingredient," Franson said.

"And there are certain things that happen to everyone who takes THC."

These, she said, are a feeling of pleasure or high, motor instability, decreased reaction time, attention deficit and increased heart rate.

"People think it mellows them out, but it causes an average increase in heart rate of 16 beats per minute," Franson said. "That's why people who take high doses they are unaccustomed to can experience significant anxiety or paranoia."

Other THC effects commonly experienced are increased appetite, decreased nausea, decreased motivation and decreased pain perception.

Additional typical effects are bloodshot eyes, decreased pressure inside the eye (it's used to treat glaucoma), heightened sensory perception (intense colors and sounds), distorted sense of time and sometimes a dry mouth.

Some effects are felt as soon as THC enters the bloodstream much more quickly if inhaled. Delivery is key joint, blunt, water pipe or a volcano (in which vapor only is collected in an expandable bag). Effects typically last an hour to a few hours, but the fat-soluble chemicals stay in the body for much longer.

Absorption of ingested THC is much slower.

After the high is over, some users feel sleepy or depressed.

Whatever is happening, Franson said, it's THC that's doing it.

"I think it all has to do with dose. The rest is marketing," Franson said. "It's folklore."