Poster Session 04 Program Schedule
02/15/2024
12:00 pm - 01:15 pm
Room: Majestic Complex (Posters 61-120)
Poster Session 04: Neuroimaging | Neurostimulation/Neuromodulation | Teleneuropsychology/Technology
Final Abstract #61
Do Depressive Symptoms Mediate the Association Between External Locus of Control and MRI Markers of Risk for Alzheimer’s Disease and Related Dementias in Racially and Ethnically Diverse Middle-Aged Adults?
A. Zarina Kraal, Columbia University Irving Medical Center, New York, United States
Adam Brickman, Columbia University Irving Medical Center, New York, United States
Jennifer Manly, Columbia University Irving Medical Center, New York, United States
Category: Neuroimaging
Keyword 1: depression
Keyword 2: neuroimaging: structural
Keyword 3: diversity
Objective:
External locus of control or perceived constraints is the belief that life’s outcomes are disproportionately influenced by outside forces (e.g., social structures and institutions). Greater external locus of control is associated with more depressive symptoms and poorer cognition in middle-aged and older adults. However, the association between external control and MRI markers of risk for Alzheimer’s disease and related dementias (ADRD), and potential pathways underlying this association, remain unknown. We hypothesized that the association between external locus of control and MRI markers would be partially mediated by depressive symptoms.
Participants and Methods:
Participants were middle-aged adults in the Offspring Study of Racial and Ethnic Disparities in Alzheimer’s Disease in New York City (N=448; age: M=53.3 (SD=10.4), 64.7% women, 65.4% Latinx, 23.4% non-Latinx Black, 11.2% non-Latinx White) who underwent MRI and completed self-report questionnaires. External locus of control was assessed with eight items from the Perceived Control scale. Depressive symptoms were assessed using the 14-item Center for Epidemiologic Studies Depression Scale. MRI markers included white matter hyperintensity (WMH) volume and cortical thickness averaged from AD signature regions. Mediation models estimated the indirect effect of external locus of control on MRI markers through depressive symptoms, adjusting for age.
Results:
Depressive symptoms mediated the association between external locus of control and cortical thickness (standardized indirect effect=0.048, SE=0.021, 95% CI: [0.007, 0.090]). In contrast, depressive symptoms did not mediate the association between external locus of control and WMH, as depressive symptoms were not associated with WMH.
Conclusions:
External locus of control may adversely affect brain health in midlife via neurodegenerative rather than cerebrovascular processes, though additional research using other indicators of cerebrovascular disease (e.g., microbleeds) is necessary. Indeed, experiences of constraints may trigger a cascade of psychological and biological stress-related processes, such as depressive symptoms, which, in turn, may contribute to worse brain health. Our findings point to depressive symptoms as a potential pathway through which external locus of control may adversely impact brain health among racially and ethnically diverse middle-aged adults.
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