Loss of Pleasure Linked to Early-Onset Dementia Not Alzheimer's, New Study Finds

A study published in Brain indicates that loss of the ability to experience pleasure is unique to early-onset dementia, or frontotemporal dementia (FTD), but not Alzheimer's disease, reports Genetic Engineering & Biotechnology News . Scientists said this is the first study to associate FTD with anhedonia. Neuroimaging showed gray matter deterioration in the pleasure centers of the brain that differ from brain regions linked to depression or apathy. The authors found marked degeneration in the reward-seeing centers of the brain, including the frontal and striatal areas, in FTD patients. Such individuals exhibited a dramatic decline from pre-disease onset, compared to patients with Alzheimer's disease, who did not show clinically significant anhedonia. Patients with early-onset dementia are frequently misdiagnosed with depression and other neuropsychiatric disorders, potentially because anhedonia also occurs often in people with depression, bipolar disorder, and obsessive-compulsive disorder. The distinctiveness of brain regions associated with early-onset dementia revealed by this study may lead to targeting these regions to develop specific treatments. "Our findings point to the importance of considering anhedonia as a primary presenting feature of behavioral variant FTD and semantic dementia, with distinct neural drivers to that of apathy or depression," the researchers concluded.