The average number of prescriptions per person dispensed in the last two decades has doubled from eight a year to 16 despite most people living longer and healthier lives, a study has shown.

The research paper, published in the Social Science & Medicine journal, accused pharmaceutical companies of “disease mongering”, arguing they massaged statistics and defined an increasing number of conditions, such as attention deficit hyperactivity disorder and high cholesterol, as diseases purely for the pursuit of profit.

Study author Professor Joan Busfield, of Essex University, said: “I think drugs are being overused. The population is getting healthier and healthier, longevity is increasing, but we are using more and more drugs.”

The professor also attacked the intensive marketing practices of drug companies, claiming that while doctors said their prescription choices were not influenced by the industry, research showed otherwise.

“The evidence indicates it is and that even small gifts can influence behaviour,” she said.