A new study finds that people taking anti-anxiety and sleep medications have a greater risk of premature death than those who do not take the drugs.

Could anti-anxiety or sleeping pills be deadly? After many years of suspicion, a new study in the journal BMJ has linked the drugs to an increased risk of death.

For more than seven years, researchers followed 34,727 people who took anti-anxiety medications such as Valium and Xanax, or sleep aids like Ambien, Sonata, and Lunesta. They compared government data from these individuals to data from 69,418 people who did not take the drugs.

The researchers found that those who took the prescription drugs had more than double the risk of death from any cause. They also discovered that there were four extra deaths per 100 people associated with the drugs, who lived for an average of 7.6 years after first being prescribed.

The most common drugs taken by study participants were Diazepam (Valium), Temazepam (Restoril), and Zopiclone, which is known as a Z-drug and is in the same family as Ambien and Sonata. (Zopiclone is not commercially available in the U.S.)

“This study adds to the evidence that these drugs are dangerous,” explained Scott Weich, a psychiatry professor at the University of Warwick, who led the research.

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Anxiolytic and hypnotic drugs are addictive and are also associated with cognitive and psychomotor impairments, potentially leading to falls and injuries.

Based on data from the study, Weich said that many subjects were found to take more than one of the study drugs, but they did not look at whether the medications were consumed at the same time and cannot say if drug combinations had an impact on mortality.

“We’ve known for decades that benzodiazepines are addictive, that they can cause long-term problems with memory, concentration, and balance, and that they are associated with traffic accidents,” he said. “But this and other studies show that they are also associated with increased rates of death.” As with previous studies, Weich said that the risk and drug dosage were correlated.

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Dr. Steven H. Feinsilver, director of the Center for Sleep Medicine at Mount Sinai’s Icahn School of Medicine, said that Weich’s study isn’t the first to suggest a link between the use of hypnotics and mortality.

“However, studies such as these do not necessarily mean that the use of these drugs increases the risk death,” he said. “Patients are given these drugs for a reason, and there is evidence that poor sleep itself is associated with a higher risk of illness and death.”

Feinsilver said that sleep improvement with pills is relatively small, and most insomnia should be treated either by finding and addressing the underlying cause, or by improving the patient’s sleep behavior.

Weich expressed caution in drawing conclusions from the study. “Even though we controlled for a very wide range of medical and psychiatric conditions, observational research can never be conclusive or prove causal relationships,” he said, adding that a “consistent picture of harm does emerge when you look at all the studies together.”

“The reason this matters so much is because of the very large numbers of prescriptions that continue to be written for these drugs,” Weich emphasized.

Dr. Mildred Frantz, who runs a private medical practice in Eatontown, N.J., said that prescribing sleeping pills and anti-anxiolytics in the long-term has always been troubling for physicians.

“There are certainly some patients that have a true need for these medications in order to have a good quality of life, however they are addictive and have many side effects; especially with an aging population,” she said.

“I also worry about patients relying on the medication instead of changing sleep hygiene and lifestyle stressors, which may be able to solve the underlying issue,” she added.

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