<<Disclaimer: Verify this information before applying it to your situation.>>

I know that low T3, the thyroid hormone, contributes to depression.  Also, there is a huge link between hashimotos thyroid disease and gluten antibodies.  Here is what a search reveals - some articles for you:
http://www.stopthethyroidmadness.com/?s=gluten&search=********One of my most prevalent symptoms is depression when I ingest gluten.  Prior to celiac disease prognosis I probably would have been classified manic depressive or bipolar.  If your friend tests negative then you can always suggest it, what does going gf hurt?********Anxiety but not depression decreases in coeliac pa... [Scand J Gastroenterol. 2001] - PubMed result
     http://www.ncbi.nlm.nih.gov/pubmed/11346203As co-author of a new book titled “Cereal Killers” slated for release in the fall of 2009, the study of the impact of gluten continues to be a driving passion in my life. 

I am fascinated by the way that gluten induces illness and impedes learning while it alters mood, behavior, and a host of other facets of human existence. Sure, gluten’s impact on health is an important issue, but that is only the most obvious area of impact. Mood disturbances, learning disabilities, and the loss of quality of life due to psychiatric and neurological illness are even more tragic than the plethora of physical ailments that are caused or worsened by gluten.  The further I go down this rabbit hole, the more I realize that grains are a good food for ruminants - not people. I teach at the Royal Roads University, Continuing Studies.********Great article that is research supported. This is the link: http://members.shaw.ca/ron_hoggan//psychiatric issues.htm********Denise, there is a sure connection between emotional and mental health issues and celiac/gluten-intolerance. It is called the brain-gut connection. The gut is like a brain. When
 we feel scared we feel it in our gut, but the emotion is really coming from the brain. Thus, the saying "I have butterflies in my stomach". Go to celiac.com and read the excerpts from Ron Hoggan's book "Dangerous Grains". For a lot of celiacs the first thing that is noticeable is the depression, mood swings, insomnia, bi-polar symptoms. I will forward some articles to you.
In Baton Rouge we have a CDF support group and a social worker here, Johnny Patout, started a Celiac Emotional Healing Support Group. He facilitates the group. It is not about food or lifestyle, it is about healing from past disappointments with the medical community, emotional issues, depression, managing the diet positively and seeing our disease as the blessing it is.
I would say no he should not delete gluten. He should find a Dr. that will listen to him, believe him, and test him. He is probably having some other problems besides depression too. If he eliminates gluten now he may never get a proper diagnosis.********



*Support summarization of posts, reply to the SENDER not the Celiac List *
Archives are at: Http://Listserv.icors.org/SCRIPTS/WA-ICORS.EXE?LIST=CELIAC