Psychiatry, neuroradiology researchers find imaging markers of inheritable depression
Children are at heightened risk of major clinical depression when at least one parent has a history of the disorder. New research shows depression markers appearing on structural and functional brain MRI ahead of symptoms in these “familial risk” offspring from infancy through early adulthood.
The study was conducted at Dalhousie Medical School in Halifax, Nova Scotia, and published online this month in Developmental Cognitive Neuroscience [1].
Psychiatrist Rudolf Uher, MD, PhD, neuroradiologist Matthias Schmidt, MD, and co-authors searched the relevant literature, retrieving 44 studies meeting their inclusion criteria. The studies represented more than 18,5000 offspring with familial risk for depression ranging in age from 4 weeks to 25 years.
The authors state they allowed such broad age parameters in order to include early brain development, when structural and functional gains are especially fast, as well as periods when depression is most likely to become symptomatic.
Toward Better Understanding of ‘Neural Markers Indexing Vulnerability’ to Depression
While documenting various functional and structural similarities between adults and children with depression—the most common across ages being reduced cortical thickness, white matter integrity and striatal reward processing—Uher and colleagues suggest their findings are only an early look at the phenomenon of familial risk for depression that’s observable on brain imaging.
The consistency of the brain alterations among parents and their children “presents the possibility of the existence of familial neural risk factors for depression and underlies the importance of additional research,” the authors write.
“Additional studies reproducing current results, streamlining fMRI data analyses and investigating underexplored topics (i.e intracortical myelin, gyrification, subcortical shape) may be among the next steps required to improve our understanding of neural markers indexing the vulnerability to depression,” they add.
Future Research into Familial Risk Might Help Head off—and Thus Reduce—the ‘Burden of Depression’
Citing prior research showing depression is more common in females than males, Uher and co-authors note 29 of the 44 studies in the present review concentrated on the effect of only maternal depression on progeny’s brains.
However, they add, there’s compelling research showing paternal depression corresponding with “varying psychological and behavioral outcomes” in both male and female offspring.
More:
Future studies need to compare the effects of maternal and paternal depression on offspring brain development and whether any sex-specific associations are present. … Additional research on brain alterations detected in older male and female FHR youth could provide insight into the presence of possible sex-specific neural markers, which could elaborate on the varying phenotypic presentation of depression in males and females.”
Summarizing the overall import of the project, Uher and colleagues state that, by improving detection and tracking of neural markers for major depressive disorder, future research in this vein may facilitate “earlier implementation of interventions to reduce the burden of depression.”
The study is available in full for free.