Adults in the US are more likely to be given a combination of two or more drugs today than ten years ago, according to a new report.

Psychiatric drug combinations are regularly given to patients with depression, panic disorder and schizophrenia but little is known about their long-term side effects, researchers at the Bloomberg School of Public Health at John Hopkins University in Baltimore told Reuters.

The study, conducted in collaboration with the Columbia University Medical Center and New York State Psychiatric Institute, found that giving patients two types of antidrepressants or using one with a sedative or mood stabiliser were the most common combinations.