Long-term fluctuations in depressive symptoms not associated with other markers of brain health in middle age, new research published in Psychiatric Research Journal. The results suggest that the link between the trajectories of depressive symptoms and brain health may only emerge at the end of life.
“As psychiatric epidemiologists, our goal is to advance understanding of the development, determinants and consequences of psychiatric phenotypes such as depressive symptoms,” said study authors Annemarie Luik and Isabel Schuurmans of the Medical Center. Erasmus MC student in Rotterdam.
“Through this study, we wanted to unravel how depressive symptoms develop over time and how these symptom trajectories are associated with subsequent brain health. This information can in turn inform the development of interventions and treatments to promote brain health in people with depression.
For their study, the researchers analyzed data from 1,676 participants in the ORACLE (Origins of Alzheimer’s Disease Across the Life Course) study, which conducted follow-up assessments of previously pregnant women and their partners whose birth date delivery was between April 2002 and January 2006. .
The mothers and their partners completed assessments of depressive symptoms at mid-pregnancy, three years postpartum, ten years postpartum, and during the brain scan session. The neuroimaging scans were taken 15 years after giving birth, when the participants were around 47 years old on average.
“In this study, we identified weak to no associations between depressive symptom trajectories and midlife brain health,” the researchers told PsyPost. They analyzed markers of brain health such as gray and white matter volume, white matter lesions, brain microhemorrhages and subcortical structures.
“This finding contrasts with a study that focused more on end of life, which found associations between depression symptom trajectories and brain health. Therefore, the takeaway here would be that the changes in depression symptoms may not have a major impact on brain health in middle age, but that this relationship may not become important until later in life.
Luik and Schuurmans also highlighted a particularly surprising finding.
“We found that participants with mild but increasing depressive symptoms over time had greater cortical thickening in a small brain region of the lateral occipital cortex,” they explained. “This finding was unexpected, because unlike previous literature on depression, we found more cortical thickness than less.”
“Furthermore, the region has been implicated in responding to visual form information and object processing, which is not a typical feature of depression. Together, this could imply that visual processing is increased in people with more depressive symptoms, but more research should be done to ensure that this finding was not an incidental finding.
The study, like all research, comes with some caveats.
“The first measurement of depressive symptoms took place while our participants were expecting a child. Although pregnancy in general is seen as a positive life event, women also experience reduced physical health and more depressive symptoms during this time,” Luik and Schuurmans said.
“It is therefore possible that the measure of depressive symptoms during this period was more severe because of the pregnancy. More research is needed to understand whether depressive symptoms during pregnancy have a different effect on brain health than depressive symptoms at other times in life.
The study, “10-year trajectories of depressive symptoms and subsequent brain health in middle-aged adults,” was authored by Isabel K. Schuurmans, Sander Lamballais, Runyu Zou, Ryan L. Muetzel, Manon HJ Hillegers , Charlotte AM Cecil and Annemarie I. Luik.