An advertising campaign warning of the links between cannabis use and mental health damage was launched today.
In the television advert, the negative effects of the drug - memory loss, paranoia, memory loss and panic attacks - appear as unwanted guests at a party in the user's brain.
Cannabis user Simon smokes a joint and at first feels giggly, talkative and craves food, before the side effects of the drug take over.
The £2.2million campaign, which follows the reclassification of cannabis into Class B last month, is targeted at 11-18 year olds.
It urges youngsters with questions about the drug to "Talk to Frank" by calling an information line or visiting the campaign website.
Frank spokesperson Chris Hudson said: "Cannabis is the most commonly used illegal drug in Britain and 'binge smoking' to achieve maximum effect may be putting peoples' mental health in serious danger.
"There is evidence of a link between cannabis and mental health problems such as schizophrenia, and those who first use it at an early age may be more at risk.
"You never truly know what you're getting and stronger cannabis, such as skunk, can increase the chance of suffering a nasty reaction."
Marjorie Wallace, chief executive of mental health charity Sane, said: "This is a victory for the campaigning of Sane and other organisations who have for years been warning about the direct effects of cannabis in damaging the minds of young people, particularly if they take skunk and smoke from an early age.
"We need hard-hitting campaigns like this to convince people just how frightening the effects of cannabis can be, and that for those who are vulnerable, taking it may not be just chilling out for an evening but could mean robbing themselves of their chances in life."
New penalties for cannabis users were introduced when the drug was reclassified.
Anyone caught in possession of the drug is now given a warning, followed by a fine and prosecution for a third offence. Dealers can be jailed for up to 14 years.