Hmmm....don't have chrohs disease (Was posting stuff about leaky butt solutions). But I have suffered with depression a lot on and off over the years....usually got it over from thinking about other problems or illnesses I had.
In terms of vitamins and medicines SSRIS have had some success, but high doses of vitamin D has been just as effective! You need to take a lot though, try the 5,000 iu tablets several times a day....most tablets are just like 1,000 iu and don't do anything...your body absorbs about 30,000 iu from tanning for about 30 minutes.
I take about 25,000 ius daily, and it seems to work just as good or better than SSRIs. Also you can go outside in the sun more, but that requires us to go outside which is not very fun! But in all seriousness, going outdoors and exercising is probably the most effective way to combat depression....just requires us to exert energy which sucks!
If not taking vitamin D everyday or not taking much...I notice I get depressed within like 3 days. Its so obvious how effective it is....Also its great for other parts of your body, for example my gums never bleed when taking vitamin D....even if I don't floss or brush for weeks on end! No more cavities either...
Also try fish oil too. Oh, and I used to juice like 10 carrots, a beet, apple, some other **** daily....that gave me so much energy and put me in such a good mood even like only 2 days after starting juicing!
Also I have a lot of other issues that cause my depression...while I don't have Crohn's disease I have other ones that cause me to get upset like my life is over or scare me shitless. DISTRACTION is key here. If you just sit around thinking about your illness you will get more anxiety and depression over it! Everytime you start thinking that way you need to distract your mind....Needs to be more than going for a walk too....your mind needs to be focused on something else, I like to write or play videogames or watch a movie....hanging out with friends is probably good too, but I don't have many of those!
PS- Don't distract yourself to the point of not even thinking about your illness, but not thinking about it most of the time is probably good. Just keep your mind active on something else you enjoy that is engaging.
Support communites have helped me from time to time...but going to them too much caused me to constantly think about my problems. That includes coming here....you should come here for support, just not all the time because that will cause you to obsess over your problems more. Might be different for you though....