You are a social worker in private practice. More than a handful of your clients

You are a social worker in private practice. More than a handful of your clients in the past few years have been treated by a local psychiatrist who routinely puts his patients on massive doses of benzodiazepine —even patients without a discernable anxiety disorder. Some of your clients report that the medications are helpful. What is your ethical responsibility How do you proceed
?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7786299/