New research bolsters the belief that long-term use of a prescription drug commonly used to alleviate anxiety, panic attacks and sleep problems is linked in aging patients to a higher risk of Alzheimer’s disease.

Researchers in France and Canada, using data from Quebec’s health insurance program, found that Alzheimer’s risk was up to 51 percent higher in elderly people who used benzodiazepines for three months or more. The researchers said the link appeared even stronger with longer duration of use or longer-acting benzodiazepines.

The team said it wasn’t clear whether the link between Alzheimer’s and benzodiazepines — which are marketed under brands such as Xanax, Ativan, Valium and Klonopin — was causal. The researchers also noted that it was possible that anxiety and sleep disorders could be associated with early symptoms of Alzheimer’s.

But the researchers also said the link between duration and use of the drugs suggests a possible direct connection worthy of further investigation. They urged physicians to use caution in prescribing the drugs to elderly patients.

The researchers — led by Sophie Billioti de Gage and Antoine Pariente at the University of Bordeaux — used data from Quebec’s public drug plan to track 1,796 Alzheimer’s cases over six years. The patients were at least 66 years old, living in the community and covered by the drug plan between 2000 and 2009. All had used benzodiazepines at least five years prior to the first diagnosis of Alzheimer’s — a criterion selected by the researchers to guard against finding possible reverse causation. The patients’ records were then compared with 7,184 control cases.

The study — which appeared Tuesday in the British Medical Journal — was in line with five previous studies that found an increased risk of Alzheimer’s and long-term use of benzodiazepines. An accompanying editorial in the medical journal — co-authored by Kristine Yaffe at the University of California at San Francisco and Malaz Boustani at Indiana University’s Center for Aging Research — noted that the 2012 American Geriatrics Society’s list of inappropriate drugs for older adults was updated to include benzodiazepines because of undesirable side effects on cognition.