How do sleep, mood, and appetite relate to Alzheimer's?

Brain scans of people with mild cognitive impairment and memory loss reveal a substantial decrease in serotonin levels, according to Gwenn Smith, PhD, the Richman Family Professor for Alzheimer’s and Related Diseases at the Johns Hopkins School of Medicine.

Serotonin is a natural chemical in the brain which regulates sleep, mood, and appetite.

“Previous studies have shown that people with Alzheimer’s have a significant loss of serotonin in the brain,” Smith says, but seeing such a decrease in the early stages suggests serotonin loss could be a driver rather than an effect of the disease.

In her research, Smith uses neuroimaging like PET scans and fMRIs of the living brain to identify vulnerability to cognitive decline in late life. Detecting the earliest neurochemical changes could lead to more effective treatments to slow the progression of Alzheimer’s disease and other dementias, she explains.

While Smith’s imaging methods have mainly focused on understanding the functional neuroanatomic and neurochemical mechanisms related to geriatric depression, mild cognitive impairment, and Alzheimer’s disease, they have also been applied to other neuropsychiatric disorders including schizophrenia and traumatic brain injury.