Structural Correlates of Depressive Symptoms in Prodromal Alzheimer’s Disease
Javier Olazarán *
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain and Gregorio Marañón University Hospital, Madrid, Spain.
Pablo García-Polo
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain.
Daniel García-Frank
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain.
Alicia Quirós
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain.
Juan Antonio Hernández-Tamames
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain.
Carmen Acedo
La Paz University Hospital, Madrid, Spain.
Juan Álvarez-Linera
Alzheimer Disease Research Unit, Alzheimer Center Reina Sofía Foundation - CIEN Foundation, Carlos III Institute of Health, Madrid, Spain.
Ana Frank
La Paz University Hospital, Madrid, Spain.
*Author to whom correspondence should be addressed.
Abstract
Background/Aims: We conducted a cross-sectional study to investigate the structural magnetic resonance imaging correlates of depressive symptoms at the initial clinical stages of Alzheimer’s disease (AD).
Methods: Subjects aged 65 or more were categorized as prodromal AD (n=18), mild AD (n=35), or normal cognition (n=76). Depressive symptoms were measured by means of the 15-item abridged version of the Geriatric Depression Scale. Potential gray matter correlates of depressive symptoms were analyzed using the Statistical Parametric Mapping software package.
Results: Significant results were obtained in the prodromal AD group only. In that group, depressive symptoms were related to atrophy in the left precentral gyrus (Brodmann area 6) (p≤0.01, FWE corrected).
Conclusion: Our results, added to the existing literature, suggest that dysfunction in left-sided, cognitively and functionally salient, cortical regions along with relative preservation of deficit awareness, provided by the right hemisphere, explain depressive symptoms in the initial clinical stages of AD.
Keywords: Alzheimer’s disease, depression, magnetic resonance imaging, structural correlates.