Mindfulness meditation worked as well as a standard drug for treating anxiety in the first head-to-head comparison.

The study tested a widely used mindfulness program that includes 2 1/2 hours of weekly classes and 45 minutes of daily practice at home. Participants were randomly assigned to the program or everyday use of a generic drug sold under the brand name Lexapro for depression and anxiety.

After two months, anxiety, as measured on a severity scale, declined by about 30 percent in both groups and continued to decrease during the following four months.

Study results, published last Wednesday in the journal JAMA Psychiatry, are timely. In September, an influential U.S. health task force recommended routine anxiety screening for adults. Numerous reports suggest global anxiety rates have increased recently, related to worries over the pandemic, political and racial unrest, climate change, and financial uncertainties.

Anxiety disorders include social anxiety, generalized anxiety, and panic attacks. Affected people are troubled by persistent and intrusive worries that interfere with their lives and relationships. In the U.S., anxiety disorders affect 40 percent of U.S. women at some point in their lives and more than 1 in 4 men, according to data cited in U.S. Preventive Services Task Force screening recommendations.

Mindfulness is a form of meditation that emphasizes focusing only on what’s happening at the moment and dismissing intrusive thoughts. Sessions often start with breathing exercises. Next might be “body scans” — thinking about each body part systematically, head to toe. When anxious thoughts intrude, participants learn to acknowledge them briefly but then dismiss them.

Instead of ruminating over the troubling thought, “you say, ‘I’m having this thought, let that go for now,”’ said lead author Elizabeth Hoge, director of Georgetown University’s Anxiety Disorders Research Program. With practice, “It changes the relationship people have with their own thoughts when not meditating.”

Previous studies have shown mindfulness works better than no treatment or at least as well as education or more formal behavior therapy in reducing anxiety, depression, and other mental woes. But this is the first study to test it against a psychiatric drug, Hoge said, and the results could make insurers more likely to cover costs, which can run $300 to $500 for an 8-week session.

The results were based on about 200 adults who completed the six-month study at medical centers in Washington, Boston, and New York. Researchers used a psychiatric scale of 1 to 7, with the top number reflecting severe anxiety. The average score was about 4.5 for participants before starting treatment. It dropped to about three after two months, then dipped slightly in both groups at three and six months. Hoge said the change was clinically meaningful, resulting in a noticeable symptom improvement.

Ten patients on the drug dropped out because of troublesome side effects possibly related to treatment, which included insomnia, nausea, and fatigue. There were no dropouts for that reason in the mindfulness group, although 13 patients reported increased anxiety.

The study “is reaffirming about how useful mindfulness can be when practiced effectively,” said psychologist Sheehan Fisher, an associate professor at Northwestern University’s Feinberg School of Medicine who was not involved in the study.