People with early-onset dementia are often mistaken for having depression and now Australian research has discovered the cause: a profound loss of ability to experience pleasure - for example a delicious meal or beautiful sunset - related to degeneration of 'hedonic hotspots' in the brain where pleasure mechanisms are concentrated.
The University of Sydney-led 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 findings were published today in the leading neuroscience journal, Brain.
Profound loss of pleasure related to early-onset dementia | EurekAlert! Science News