Aug. 21 (HealthDay News) -- Loss of interest in previously enjoyable activities is a common sign of depression -- and it's a neurological response that researchers can actually see in the brain.

When listening to their favorite music, depressed people showed less activity in regions of the brain that are involved with experiencing pleasure and processing rewards compared with healthy people, Canadian researchers found.

In the study, the researchers asked 15 non-depressed people and 16 people recently diagnosed with depression for a list of their favorite music and music that they felt neutral about (neither liked nor disliked). Participants then listened to their musical selections for three minutes.

Functional magnetic resonance imaging (fMRI) scans of the brain showed that the non-depressed participants had more neural activity in several areas of the brain associated with reward processing and pleasure than depressed participants did, according to the report published in the Aug. 26 issue of the journal NeuroReport.

The researchers said the findings show a neurological underpinning for a common depressive symptom and suggest that depression can interfere with enjoyment of something as basic as music.

"Our results revealed significant responses within the areas of the brain that are associated with reward processing in healthy individuals. They also showed significant deficits in these neurophysiological responses in recently depressed subjects compared to the healthy subjects," Dr. Elizabeth Osuch, a researcher at the Lawson Health Research Institute in Ontario, said in a news release from the journal's publisher.

The findings may suggest new treatments for depression, the study authors said.

"If we can target these areas of the brain through treatment, we have the potential to treat depression earlier, right at the source," Osuch added.

SOURCE: NeuroReport, news release, Aug. 18, 2009