A recent study from the University of Sydney has determined that the loss of a person’s feelings of pleasure and happiness could be an early indicator of FTD.

The study, published in the journal Brain, analyzed the connection between the brain deterioration caused by FTD and a person’s experience of feeling pleasure. Of the 172 people that participated in the study, 87 of them were diagnosed with FTD and 34 had Alzheimer’s.

Researchers asked caregivers and care partners to evaluate the diagnosed person’s happiness levels pre-and post-diagnosis. The team also used imaging technology to conclude that the loss of joy reported in people with FTD was related to the deterioration of their brain’s pleasure system. Participants who had Alzheimer’s did not experience the same striking loss of pleasure as the FTD participants.

Professor Muireann Irish of the University of Sydney, who has worked on this project for seven years, said in an article published by the Australian Broadcasting Corporation’s news site (ABC News) that patients with FTD showed a “marked drop from their pre-dementia [happiness] ratings to the current moment.”

She continued, “We know [people with FTD] become extremely withdrawn and quite apathetic and lose interest in social engagements, in hobbies they used to pursue. They end up becoming very withdrawn and isolated. All these signs point to perhaps there is a blunting, or a dampening of pleasure in these patients, and that’s exactly what we found in this study.”

The study determined that this loss of pleasure could be an early indicator for the pathological process of FTD long before doctors are able to see changes in a person’s memory or cognition.

“I think we could go as far as saying this is an unrecognized symptom of [FTD],” Irish said.

Read the full ABC News article here.