Cognitive behavioral therapy - a type of talking therapy - coupled with antidepressants reduces symptoms of depression in people who have been diagnosed with treatment-resistant depression, a new study has found.

The study, conducted by researchers from Universities of Bristol, Exeter and Glasgow, says that cognitive behavioral therapy can be the next step to take if a person has stopped responding to medications for depression.

Cognitive behavioral therapy is a blend of two therapies - cognitive therapy (CT) and behavioral therapy. The therapy helps a person to focus on his or her problems and act upon them. The therapist also helps the patient seek more positive ways to deal with the problems and avoid negative or unhelpful thinking.

The study included 469 people, between ages 18 and 75, diagnosed with treatment-resistant depression. The participants were randomly divided into two groups; one group received usual care from the physician while the other group received the standard care for depression plus cognitive behavioral therapy.

After six months of therapy, researchers found that 46 percent of people who received CBT in addition to regular care reported a 50 percent reduction in depression symptoms compared to just 22 percent reduction seen in patients who had received usual care. The benefits of the therapy lasted for a year.

Researchers say that CBT when coupled with antidepressants helps people diagnosed with treatment-resistant depression cope with the condition and improves their quality of life.

"This research is also of great importance because it used a CBT intervention alongside treatment with antidepressants. It confirms how these approaches - the psychological and physical - treatments can complement each other. It was also encouraging because we found the approach worked to good effect across a wide range of people of different ages and living in a variety of settings," said Chris Williams, Professor of Psychosocial Psychiatry at the University of Glasgow in a news release from the University of Bristol.

The study is published in the journal The Lancet.