The journalist joined ex-MP Matthew Parris and former royal correspondent Jennie Bond in a scientific trial approved by the Home Office.
Viewers will see the trio take part in the test that will look at the effects on the brain of two different forms of cannabis, skunk, and hash, compared to a placebo.
Snow said: “I’ve worked in warzones, but I’ve never been as overwhelmingly frightened as I was when I was in the MRI scanner after taking skunk. I would never do it again. I can fully believe this week’s figures that tell us that 25% of all psychosis treated in Britain is associated with smoking skunk.
“I had no idea it could be so powerful and terrifyingly mind altering. And I am someone who worked for three years in a drug dependence day centre.
“If many who smoke this stuff had ever seen the physical effects on the brain as displayed through the MRI scanner, they would make a more informed judgment as to what they were doing.”
The show, Drugs Live: Cannabis On Trial, will be shown on March 3.
Skunk, a more potent form of the drug, accounts for around 80% of the UK drug market and is believed to be more addictive and can provoke paranoid episodes, psychotic symptoms and memory loss.
Val Curran, who organised the trial, said: “This is a hugely exciting and important research project which will show how Skunk and hash can produce different effects on the human brain, mind and behaviour.
“My research group were concerned that cannabis addiction in the UK has increased over recent years alongside the increased market dominance of skunk.
“I hope this new programme will scientifically inform those who use, have used or are thinking of using this drug about the diverse effects of different types of cannabis.”