Here's an interesting study:
Negative mood signals body's immune response
The investigators found that negative mood measured multiple times a day over time is associated with higher levels of inflammatory biomarkers. This extends prior research showing that clinical depression and hostility are associated with higher inflammation.
“We hope that this research will prompt investigators to include momentary measures of stress and affect in research examining inflammation, to replicate the current findings and help characterize the mechanisms underlying associations between affect and inflammation,” Graham-Engeland said. “Because affect is modifiable, we are excited about
these findings and hope that they will spur additional research to understand the connection between affect and inflammation, which in turn may promote novel psychosocial interventions that promote health broadly and help break a cycle that can lead to chronic inflammation, disability, and disease.”
https://news.psu.edu/story/552547/2018/12/20/research/negative-mood-signals-bodys-immune-response