[Ghost On The Highway]

It can certainly help to take vitamins/minerals if you are deficient (especially in B-vitamins). B1 (thiamine) deficiency has been proposed as a cause for Korsakoff's syndrome in alcoholics, which is basically neurodegeneration, amnesia and all sorts of fun brain damage. Personally, I never experienced a significant benefit from supplements or fish oil, but I do eat a lot of meat, fish, and whole grains. I did notice, however, that when I was trying to lose weight (eating less) I felt very depressed, so vitamin deficiency could have been a factor. Or maybe that was just ice cream deficiency

I'll second the endorsement for St. John's Wort, although great care must be taken when combining it with SSRI antidepressants like Zoloft and Prozac. Definitely talk to your doctor before starting.