STUDY: Pot smoking ‘permanently lowers IQ’…

“For example, individuals who started using cannabis in adolescence and used it for years thereafter showed an average eight-point IQ decline.

“Quitting or reducing cannabis use did not appear to fully restore intellectual functioning among adolescent-onset former persistent cannabis users,” she said.

It meant that an average person dropped far down the intelligence rankings, so that instead of 50 per cent of the population being more intelligent than them, 71 per cent were.

But Prof Moffitt said there was growing concern in the US that cannabis was increasingly being seen as a safe alternative to tobacco.

Cannabis health dangers ‘underestimated’

A third of people think cannabis is harmless, despite it being 20 times more carcinogenic to smoke than tobacco, according to a report published today

The charity reviewed existing scientific evidence on the health impacts of smoking cannabis, and reported there was strong evidence it contributed to diseases including lung cancer, tuberculosis and acute bronchitis.

It was also “strongly associated” with suppression of the immune system and heart disease, if taken for long enough.

“Young people in particular are smoking cannabis unaware that, for instance, each cannabis cigarette they smoke increases their chances of developing lung cancer by as much as an entire packet of 20 tobacco cigarettes.”