Concerns have been raised over sleeping pills, after a study showed that they could increase the risk of death more than four-fold. The results, which were published in the journal BMJ Open, showed that the higher the dose, the greater the risk of dying, while people on higher doses were at a greater risk of cancer.

Experts from the Jackson Hole Centre for Preventive Medicine in Wyoming and the Scripps Clinic Viterbi Family Sleep Centre in California, carried out the study on more than 10,500 people taking sleeping pills.

The study included drugs used in the UK, such as benzodiazepines (including temazepam and diazepam), non- benzodiazepines, barbiturates and sedative antihistamines. The results showed that people prescribed sleeping pills were 4.6 times more likely to die during a two and a half year period compared to those not taking the drugs. Furthermore, the group of people taking the highest doses in the study were 35% more likely to develop a major cancer.