Put away the duvet if you want a good night's sleep – you're best off sliding under a heavy blanket.

Scientists say weighted blankets trigger the release of feel-good chemicals in the brain, which reacts to the blanket's pressure as it would to an embrace or cuddle.

Tests show this puts you in a better mood in the morning – and cuts cases of depression and anxiety.

'Weighted blankets might be a safe and effective intervention for insomnia and various sleep disturbances, with fewer side-effects than drug therapy,' report the researchers.

They analysed data from studies looking at heavy or weighted blankets as a treatment for improving sleep and other disorders, in an effort to understand mechanisms behind sleep problems.

A woman sleeping on a sofa under a blanket. Scientists say weighted blankets trigger the release of feelgood chemicals in the brain, which reacts to the blanket's pressure as it would to an embrace or cuddle (stock image)

Neurologists at Zhejiang University Hospital in Hangzhou, China, (pictured) concluded that Lying under weighted blankets results in better sleep and fewer cases of chronic pain 

Lying under weighted blankets results in better sleep and fewer cases of chronic pain, conclude the neurologists at Zhejiang University Hospital in Hangzhou, China.

Just how heavy blankets have such a dramatic effect is unclear.

One theory is that the touch and pressure of a weighted blanket on the skin can stimulate sensory nerve endings.

The researchers suggest this would activate the parasympathetic nervous system, which has a calming effect.

It also increases the production of endorphins, the body's own painkillers, and boosts levels of dopamine and serotonin, brain chemicals involved in the regulation of mood disorders.

Endorphins and dopamine can also reduce heart rate and relax muscles, which in turn can improve sleep and limit insomnia.

Stimulation of the nerve endings may also encourage release of melatonin, the hormone which plays a key role in sleep timing.

The body naturally increases melatonin levels at night to aid sleep, while supplements based on the hormone are used by doctors to treat insomnia.

The neurologists say: 'The blankets could improve sleep quality and ease negative emotions and daytime symptoms in patients with sleep disorders, attention deficit hyperactivity disorder and other related disorders.'

But the study, published in Frontiers in Psychiatry, concludes that more research will be needed.