Depression is Associated with Tau and Not Amyloid Positron Emission Tomography in Cognitively Normal Adults

Article type: Research Article

Authors: Babulal, Ganesh M.^{a; b; *} | Roe, Catherine M.^{a; b} | Stout, Sarah H.^{a; b} | Rajasekar, Ganesh^{a; b} | Wisch, Julie K.^b | Benzinger, Tammie L.S.^{a; c; d; h} | Morris, John C.^{a; b; c; d; e; f; g} | Ances, Beau M.^{a; b; c}

Affiliations: [a] Charles F. and Joanne Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA | [b] Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA | [c] Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA | [d] Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA | [e] Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA | [f] Department of Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA | [g] Department of Occupational Therapy, Washington University School of Medicine, St. Louis, MO, USA | [h] Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA

Correspondence: [*] Correspondence to: Ganesh M. Babulal, Department of Neurology, Washington University School of Medicine, 660 S. Euclid Ave., Campus Box 8111, St. Louis, MO, USA. Tel.: +1 952 334 8536; E-mail: babulalg@wustl.edu.

Abstract: Background:Depression is also common with older age. Alzheimer’s disease (AD) studies suggest that both cerebrospinal fluid and positron emission tomography (PET) amyloid biomarkers are associated with more depressive symptoms in cognitively normal older adults. The recent availability of tau radiotracers offers the ability to examine in vivo tauopathy. It is unclear if the tau biomarker is associated with depression diagnosis. Objective:We examined if tau and amyloid imaging were associated with a depression diagnosis among cognitively normal adults (Clinical Dementia Rating = 0) and whether antidepressants modified this relationship. Methods:Among 301 participants, logistic regression models evaluated whether in vivo PET tau was associated with depression, while another model tested the interaction between PET tau and antidepressant use. A second set of models substituted PET amyloid for PET tau. A diagnosis of depression (yes/no) was made during an annual clinical assessment by a clinician. Antidepressant use (yes/no) was determined by comparing medications the participants used to a list of 30 commonly used antidepressants. All models adjusted for age, sex, education, race, and apolipoprotein ɛ4. Similar models explored the association between the biomarkers and depressive symptoms. Results:Participants with elevated tau were twice as likely to be depressed. Antidepressant use modified this relationship where participants with elevated tau who were taking antidepressants had greater odds of being depressed. Relatedly, elevated amyloid was not associated with depression. Conclusions:Our results demonstrate that tau, not amyloid, was associated with a depression diagnosis. Additionally, antidepressant use interacts with tau to increase the odds of depression among cognitively normal adults.

Keywords: Alzheimer’s disease, antidepressants, biomarkers, depression, older adults

DOI: 10.3233/JAD-191078

Journal: Journal of Alzheimer's Disease, vol. 74, no. 4, pp. 1045-1055, 2020