Chronic psychosocial stress is associated with higher MRI-visible perivascular space volumes in healthy young adults

Chronic psychosocial stress (CPS) is associated with adverse brain and mental health outcomes. Effects on the cerebral microvasculature have been proposed as an underlying mechanism, although this remains to be established. Here, we examined the association between CPS and an early marker of microvascular dysfunction, magnetic resonance imaging (MRI)-visible perivascular spaces (PVS). Analyses were conducted in two cohorts of healthy young adults (N = 61; ages 18-43 years; 88% male) using high-resolution 3T MRI and an automated PVS quantification pipeline. CPS was assessed using the Perceived Stress Scale (PSS-10). We applied a two-step meta-analytic framework and controlled for known allostatic factors impacting PVS, including age, body mass index and mean arterial pressure. In accordance with our hypothesis, individuals with higher CPS had significantly higher fractional PVS volumes in the centrum semiovale (CSO), in particular in the frontal and occipital lobes (pFDR < .05). No such effect was found in the basal ganglia, or in the CSO subdivision, parietal, and temporal lobes (pFDR > .09). Our findings indicate that CPS may contribute to subtle, centrum semiovale specific microvascular alterations even in healthy young adults. Future multimodal research including inflammatory marker and blood-brain barrier measures may help to elucidate mechanistic pathways.