New Delhi, Sep 7 : US researchers have developed a novel problem-solving therapy that boosts brain functions to relieve symptoms of depression, giving hope to millions worldwide.

Depression is a common mental disorder, which affects an estimated 5 per cent of adults globally.

The study led by a team from Stanford Medicine applied problem-solving therapy -- a form of cognitive therapy -- on adults with both depression and obesity. The therapy reduced depression in a third of the hard-to-treat patient group.

The team targeted 108 adults diagnosed with both major depression and obesity, a confluence of symptoms that often indicate problems with the cognitive control circuit.

While 59 adults underwent a year-long programme of problem-solving therapy in addition to their usual care, such as medications and visits to a primary care physician, 49 only received usual care.

The participants also underwent fMRI brain scans and filled out questionnaires that assessed their problem-solving ability and depression symptoms.

Among the problem-solving group, 32 per cent of participants responded to the therapy -- their symptom severity halved, revealed the study published in the journal Science Translational Medicine.

Lead author Xue Zhang, a postdoctoral scholar in psychiatry at the varsity called it 'a huge improvement'. It is because patients with obesity and depression have only a 17 per cent response rate for antidepressants.

Brain scans showed that in the group receiving only usual care, a cognitive control circuit that became less active throughout the study correlated with worsening problem-solving ability.

The pattern was reversed in the group receiving therapy. The decrease in activity correlated with enhanced problem-solving ability.

It may be because their brains are learning to process information more efficiently through the therapy, said the team.

While before the therapy, their brains had been working harder; now, they were working smarter, the team said.

Overall, both groups improved in their depression severity. But for some problem-solving therapy brought more clarity, allowing them to return to work, resume hobbies, and also to manage social interactions.

/IANS