Teenagers are renowned for not thinking too far into the future but scientists claim if they want to live into their old age, they should stay away from cannabis.

A new study has revealed that smoking large amounts of marijuana as a teenager increases your chances of dying before the age of 60. And it found that the risk of dying in an accident or as a result of suicide was directly proportional to how much cannabis participants had taken when young.

Researchers studies more than 45,000 men who took part in compulsory military training in Sweden in 1969 and 1970. This group of men were then followed over a 42-year period to see if they appeared on the National Cause of Death Register.

The study, carried out by scientists from Stockholm’s Karolinska Institutet, found that 4,000 of the men had died by the time the research period ended in 2011. And the participants who had used cannabis more than 50 times during their teenage years were 40 per cent more likely to die before their 60th birthday than those who had steered clear of the class-B drug.

The findings were published in the American Journal of Psychiatry. Peter Allebeck, who led the study, said: “Our conclusion is that early cannabis use can contribute to premature death, particularly through injuries and suicide, and that this is unrelated to the increased risk of psychosis.”

It is thought that early cannabis use can lead to heart problems and lung cancer. And those who use the drug usually have worse general health and are more likely to also smoke tobacco.

Drug use also linked to poorer jobs and financial difficulties

Another study, published in Clinical Psychological Science, followed people all the way from birth to the age of 38. The team of researchers found that those who regularly smoked cannabis for at least four days a week over a period of years ended up in a lower social class than their parents and in worse jobs than those who didn’t use the drug.

Lead researcher Magdalena Cerda, from the University of California, said: “Our study found that regular cannabis users experienced downward social mobility and more financial problems such as troubles with debt and cash flow than those who did not report such persistent use.

“Regular long-term users also had more antisocial behaviours at work, such as stealing money or lying to get a job, and experienced more relationship problems, such as intimate partner violence and controlling abuse.”

Employers concerned that members of their staff could be abusing cannabis can use workplace drug testing to find out for definite whether substance misuse is taking place. Hair strand tests can look at a user’s drug use over a period of months and will be able to prove whether someone is a regular long-term cannabis user.