Study uses music to trigger responses in brains of patients resistant to depression treatment

New Delhi: Western classical music can help activate brains of patients who do not respond to anti-depression treatment, according to a study.

The results, published in the journal Cell Reports, could help develop personalised music therapy plans for patients with treatment-resistant depression, in which one's depressive symptoms persist despite taking multiple antidepressants.

According to previous studies, these patients have been observed to have brain processes biased to respond more easily to sad faces, compared to happy faces.

In this study, 13 patients with treatment-resistant depression listened to pieces written by Mozart and Beethoven among others and the researchers, including those from China's Shanghai Jiao Tong University, studied their brains to understand how music produced anti-depressant effects.

For the purpose of deep-brain stimulation in these patients, the team implanted electrodes and placed them in the 'extended amygdala' circuit.

The amygdala plays an important role in one's motivation and emotional behaviour. It is located in the forebrain, which is the brain's largest part and helps with higher thinking processes, such as those involved in reasoning and language.

The 'extended amygdala' circuit connects two areas in the forebrain -- the bed nucleus of the stria terminalis (BNST), which plays a role in managing stress and the nucleus accumbens (NAc), which is involved in experiencing pleasure.

The researchers found that classical music worked as an antidepressant by harmonising activity between the three brain regions -- the auditory cortex, involved in listening, the BNST (manages stress) and the NAc (helps experience pleasure).

"The BNST-NAc circuit, sometimes referred to as part of the ‘extended amygdala,’ underscores the close relationship between this circuit and the amygdala, a central structure in emotional information processing," senior author Bomin Sun, director and professor of the Centre for Functional Neurosurgery at Shanghai Jiao Tong University, said.

"This study reveals that music induces triple-time locking of (brain waves) in the cortical-BNST-NAc circuit through auditory synchronisation," Sun said.

The synchronisation and the "antidepressant effects" were found to be more significant in patients having a high appreciation of music, compared to those having a low appreciation of music.

Most of the patients were not familiar with the Western classical pieces used in the study, the authors said.

The results helped the researchers propose personalised music therapy plans that would improve treatment outcomes, they said.

"Our research integrates the fields of neuroscience, psychiatry, and neurosurgery, providing a foundation for any research targeting the interaction between music and emotion. Ultimately, we hope to translate our research findings into clinical practice, developing convenient and effective music therapy tools and applications," Sun said.