Cannabis study offers new hope stoners can solve appetite riddle

Besides making a bongo drum sound inexplicably magical and enhancing a person's ability to talk nonsense, generations of cannabis smokers will recognise the "munchies" as one of the drug's most reliable side effects.

Now scientists have shown the insatiable urge to eat after smoking is caused by cannabinoids hijacking brain cells that normally suppress appetite.

A new study suggests cannabis causes the brain to produce chemicals that transform the feeling of fullness into a hunger that is never quite satisfied.

Scientists believe the findings, which illuminate a previously unknown aspect of the brain's feeding circuitry, could help design new drugs that would boost or suppress appetite at will.

Tamas Horvath, who led the work at Yale University, said: "By observing how the appetite centre of the brain responds to marijuana, we were able to see what drives the hunger brought about by cannabis and how that same mechanism that normally turns off feeding becomes a driver of eating.

"It's like pressing a car's brakes and accelerating instead."