Does stress cause gray hair?

Yes. Stress has been shown to speed up signs of aging — including gray hair.

When you’re stressed, your body has a fight-or-flight response and releases a hormone called norepinephrine. This causes the melanocytes — the cells that produce melanin — to move out of your hair follicles. Researchers say this helps cause gray hair.

There are a lot of factors that can affect how early your hair turns gray. These factors include a family history of premature gray hair, underlying health conditions, and living an unhealthy lifestyle.

Information as per the AAD. https://www.aad.org/public/everyday-care/hair-scalp-care/hair/gray-hair-causes