Hi Kevin

Well...this is a tough question...not knowing you or your wife.  You know her best...what do you think she would respond to?  If you need information to give to her our Deborah Gray has a downloadable guide to help in knowing if one has depression or not which you can find on this page. 

I think empathy helps...as in "Things seem rough for you lately" and then follow up with, "Is there anything I can do to help?"  You can point out your observations as in..."I have noticed that (describe behavior) and I am wondering if you might be depressed."  Tell her that there is hope...and there is treatment.  She need not suffer.  And she is not alone.

Please feel free to tell her about this site if you think it would help.  We would be glad to give support.

Let us know what else we might do for you as far as giving you resources or further suggestions.  Thanks for reaching out here.