The study shows that several anxiolytic (anti-anxiety) drugs or hypnotic drugs (sleeping pills) are associated with doubling the risk of mortality.
Although these findings are based on routine data and need to be interpreted cautiously, the researchers recommended that a greater understanding of their impact is essential.
Scott Weich, professor of Psychiatry at the University of Warwick, explained: "The key message here is that we really do have to use these drugs more carefully. This builds on a growing body of evidence suggesting that their side effects are significant and dangerous. We have to do everything possible to minimise over reliance on anxiolytics and sleeping pills."
The study accounted for other factors such as age, smoking and alcohol use, other prescriptions and socioeconomic status. The study, published in the journal BMJ, tracked 34,727 people for seven-and-a-half years on average from the time that they first received prescriptions for either an anxiolytic or hypnotic drug.
Benzodiazepines were the most commonly prescribed drug class, including diazepam and temazepam. The study also examined the effects of two other groups of drugs; the so-called 'Z-drugs' and all other anxiolytic and hypnotic drugs.
Many patients received more than one drug over the course of the study, and five percent received prescriptions for drugs from all three groups.