Children and teens with severe anxiety need both behavioral therapy and medication for the best chance of improvement, a new Yale-led analysis has found.

A prior landmark study of 488 youths between the ages of 7 and 17 had shown that cognitive behavioral therapy, the antidepressant sertraline, or a combination of drugs and therapy all improved outcomes.

As a result, many doctors and parents opted to see if behavioral therapy worked before starting medication. However, a closer look at the data showed that only the combination of drugs and therapy worked on those who had more severe cases of generalized, social and separation anxiety, according to results published Oct. 2 in the Journal of Clinical Child & Adolescent Psychology.

“In cases of severe anxiety the most sensible thing may often be to start combined treatment right away,” said co-author, Eli Lebowitz, assistant professor of psychology and psychiatry, and associate director of the Anxiety and Mood Disorders Program at the Yale Child Study Center.

The study also found that some subgroups, such as youths from lower socioeconomic backgrounds and those also diagnosed with obsessive-compulsive disorder, were more resistant to any treatment or combination of therapies.

Jerome Taylor, formerly of Yale and now at the University of Pennsylvania, is the lead author of the study. Wendy Silverman, director of the Anxiety and Mood Disorders Program, was also an author. Yale’s Michael Bloch is senior author.

Primary funding for the research was provided by the National Institute of Mental Health.