Harrison, Rachael
(2024)
Cerebral Blood Flow as a Possible Neurobiological Mechanism Explaining the Relationship Between Physical Activity and Depressive Symptoms in Older Adults.
Master's Thesis, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
The antidepressant effects of physical activity and exercise in clinical and subclinical populations is well supported, but the neurobiological underpinnings of this relationship are poorly understood. Current evidence suggests that cerebral blood flow (CBF) to the anterior cingulate cortex (ACC) and hippocampus may play a role in depression and responds to chronic exercise. Leveraging baseline cross-sectional data from the Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE), a multi-site aerobic exercise intervention, the present study aimed to (1) examine the relationship between moderate to vigorous physical activity (MVPA) and sub-clinical depressive symptoms, (2) examine the relationship between MVPA and CBF to the ACC and hippocampus, and (3) test CBF to the ACC and hippocampus as a statistical mediator between MVPA and depressive symptoms in a sample of 544 older adults. MVPA was measured using a wrist-worn accelerometer (Actigraph) and processed using GGIR. CBF was measured using a pseudo-continuous arterial spin labeling sequence for MRI, and regions of interest were extracted using FreeSurfer-derived masks. Aims 1 and 2 were tested using linear regression, and Aim 3 was tested using multiple mediation. All analyses controlled for age, race, gender, years of education, study site, BMI, and past smoking status. Results support a non-linear relationship between MVPA and depressive symptoms such that greater daily levels of MVPA were associated with fewer depressive symptoms, especially for those engaging in close to thirty minutes of MVPA per day. However, we did not find evidence for a relationship between MVPA and CBF to the ACC and hippocampus, nor significant mediation of CBF to the ACC and hippocampus in the relationship between MVPA and depressive symptoms. Our results confirm the relationship between MVPA and depressive symptoms, and do not support a mediating role of CBF in the relationship between MVPA and depressive symptoms.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
10 January 2024 |
| Date Type: |
Publication |
| Defense Date: |
14 November 2023 |
| Approval Date: |
10 January 2024 |
| Submission Date: |
21 November 2023 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
56 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Psychology |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
cerebral blood flow, physical activity, depressive symptoms, older adults |
| Date Deposited: |
10 Jan 2024 14:47 |
| Last Modified: |
10 Jan 2024 14:47 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/45560 |
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