Plasma proteomics reveals potential biological mechanisms of chronic post-stroke depression
Depression is a common neuropsychiatric complication after stroke that occurs in approximately one third of survivors. The mechanism of persisting depression risk after stroke is not well understood. We utilized plasma protein biomarker discovery to ask whether protein levels are related to chronic post-stroke depression and to gain insight into the underlying mechanism. We measured levels of 1,196 proteins in plasma from 85 participants between 5 months and 9 years after ischemic stroke, and mood was assessed with the Stroke Impact Scale mood questionnaire (SIS3).
Utilizing regression models, we found that plasma proteomic data alone predicts depressed mood. We next identified the subset of plasma proteins whose levels correlate with mood, and examined differences in key candidate proteins previously reported in major depression and acute post-stroke depression. Based on our findings, we propose a model where over-activation of the immune response in chronic stroke survivors triggers changes in serotonin activity and neuronal plasticity leading to depressed mood.
Source code, proteomics data, and clinical data for reproduction of the results are available here.