Affiliations: [a] Department of Nuclear Medicine, University of Leipzig Medical Center, Leipzig, Germany
| [b] Department of Radiology, University of Leipzig Medical Center, Leipzig, Germany
| [c] Department of Psychiatry and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany
| [d] Clinic for Cognitive Neurology, University of Leipzig Medical Center, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany
| [e] Department of Neurology, University of Leipzig Medical Center, Leipzig, Germany
Correspondence:
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Correspondence to: Jakob Leonhardi, Department of Diagnostic and Interventional Radiology, Liebigstrasse 20a, 04103 Leipzig, Germany. Tel.: +49 341 97 17400; E-mail: Jakob.Leonhardi@medizin.uni-leipzig.de.
Note: [1] These authors contributed equally to this work.
Abstract: Background:Alzheimer’s disease and depression can start with combined cognitive and depressive symptoms [1, 2]. Accurate differential diagnosis is desired to initiate specific treatment. Objective:We investigated whether amyloid-β PET imaging can discriminate both entities. Methods:This retrospective observational study included 39 patients (20 female, age = 70±11years) with both cognitive and depressive symptoms who underwent amyloid-β PET imaging and in whom clinical follow-up data was available. Amyloid-β PET was carried out applying [18F]Florbetaben or [11C]PiB. The PET images were analyzed by standardized visual and relative-quantitative evaluation. Based on clinical follow-up (median of 2.4 years [range 0.3 to 7.0 years, IQR = 3.7 years] after amyloid PET imaging which was not considered in obtaining a definite diagnosis), discrimination ability between AD-related depression and pseudo-dementia in depression/depression with other comorbidities was determined. Results:Visually, all 10 patients with pseudo-dementia in depression and all 15 patients with other depression were rated as amyloid-β-negative; 2 of 14 patients with AD-related depression were rated amyloid-β–negative. ROC curve analysis of the unified composite standardized uptake value ratios (cSUVRs) was able to discriminate pseudo-dementia in depression from AD-related depression with high accuracy (AUC = 0.92). Optimal [18F]Florbetaben discrimination cSUVR threshold was 1.34. In congruence with the visual PET analysis, the resulting sensitivity of the relative-quantitative analysis was 86% with a specificity of 100%. Conclusion:Amyloid-β PET can differentiate AD-related depression and pseudo-dementia in depression. Prospective clinical studies are warranted to confirm this result and to potentially broaden the spectrum of clinical applications for amyloid-β PET imaging.
