PEOPLE with early-onset dementia experience a profound loss of the ability to experience pleasure, says new research.
Researchers from University of Sydney believe it's the reason people with the illness are often initially mistaken for having depression.
The research revealed marked degeneration, or atrophy, in frontal and striatal areas of the brain related to diminished reward-seeking, in patients with frontotemporal dementia (FTD).
The researchers believe it is the first study to demonstrate profound anhedonia - the clinical definition for a loss of ability to experience pleasure - in people with FTD. Anhedonia is also common in people with depression, bipolar disorder and obsessive-compulsive disorder and can be particularly disabling for the individual.
In the study, patients with FTD - which generally affects people aged 40-65 - displayed a dramatic decline from pre-disease onset, in contrast to patients with Alzheimer's disease, who were not found to show clinically significant anhedonia.
The results point to the importance of considering anhedonia as a primary presenting feature of FTD, where researchers found neural drivers in areas that are distinct from apathy or depression.
The paper's senior author Muireann Irish said despite increasing evidence of motivational disturbances, no study had previously explored the capacity to experience pleasure in people with FTD.
"Much of human experience is motivated by the drive to experience pleasure but we often take this capacity for granted," Professor Irish said.
"But consider what it might be like to lose the capacity to enjoy the simple pleasures of life - this has stark implications for the wellbeing of people affected by these neurodegenerative disorders."
