SUNSHINE acts like an addictive drug and has a similar effect on the body as heroin, scientists claim.

Ultraviolet (UV) rays from the sun stimulate the production of endorphins, known as "feel good" hormones that act on the same biological pathway as opioid drugs, research shows.

The study, based on mice, suggests that the desire to bake for hours on a beach involves more than topping up a tan. It may appease our craving for a sunshine "fix", in much the same way as an addict satisfies a yearning for heroin or morphine.

Responding to the Harvard Medical School study, Dr Richard Weller, senior lecturer in dermatology at the University of Edinburgh, said: "If an 'addiction' to sun truly also exists in mankind, it suggests to me that there is a benefit to it.