Yes, it can, but you can also look at it the other way -- a big part of what protects us from mental illness are the beneficial organisms that live in our gut and intestinal tract and it is the disturbance of these organisms that allow yeast infections to find a welcome home. This often happens when we take antibiotics or eat too much sugar. Much current research is focusing on the connection between mental health and other diseases with imbalances in our beneficial bacteria. So it very well might be a chicken and egg story.
You might get some help from:
http://www.medhelp.org/forums/Womens-Health/show/81
Or other immune communities.
I believe any thing that causes stress will lower our immune systems, women and men.