Preliminary and speculative findings
Senior study author Zachary Miller, MD, an assistant professor in the UCSF Memory and Aging Center, explained the significance of the study findings of potential links between depression and autoimmunity, and anxiety and seizure. “There may be distinct underlying pathophysiological mechanisms in patients with Alzheimer’s disease who have symptoms of depression versus anxiety,” he said, acknowledging the findings “are quite preliminary and our interpretations quite speculative.”
Dr. Zachary Miller
The findings raise the question that the symptomatic presentation of greater amounts of depression in early-onset Alzheimer’s disease may be moderated by an underlying neuroinflammatory insult, he said. “If so, depression symptomatology could then be seen as a possible clinical marker of this inflammatory response and possibly be used in testing clinical endpoints for future intervention trials,” Dr. Miller said. “Similarly, if neuronal hyperexcitability in Alzheimer’s disease manifests itself as either seizure and/or anxiety, this would have significant impact for therapeutic monitoring and treatment.”
He said a multicenter study of Alzheimer’s disease cohorts would validate the findings. “At the same time, we are also interested in looking deeper into these findings, investigating the potential cognitive and neuroanatomical correlates associated with these conditions,” Dr. Miller said.
Clinical phenotyping may provide more insight into the relationship between psychosis and age of Alzheimer’s disease onset, said Vijay K. Ramanan, MD, PhD, an assistant professor of neurology at Mayo Clinic in Rochester, Minn.
Dr. Vijay K. Ramanan
“Less typical presentations of Alzheimer’s disease, such as posterior cortical atrophy or dysexecutive Alzheimer’s disease, are associated with younger age of onset and are sometimes misdiagnosed as having pure psychiatric disease,” he said. “It is also possible that, in some cases with psychiatric disease, a younger age of onset of cognitive symptoms is charted, even though there are fundamentally two distinct processes at play – a psychiatric disease and a separate neurodegenerative disease – each having independent but additive impacts on cognition.”
Dr. Ramanan added, “This work is also a good reminder to be on the lookout for neuropsychiatric symptoms, treat where indicated, and be open to the possibility that psychiatric symptoms and Alzheimer’s disease can coexist.”
Ms. Eijansantos, Dr. Miller, and Dr. Ramanan have no relevant financial relationships to disclose.