Stress

Psychological stress and testicular function: a cross-sectional study of 1,215 Danish men.
https://www.ncbi.nlm.nih.gov/pubmed/26477499
- No association between stress and testosterone
- Significant association between stress and semen quality.

https://www.ncbi.nlm.nih.gov/pubmed/1661182?dopt=Abstract

https://www.ncbi.nlm.nih.gov/pubmed/27561694