One pattern I've run across is a group of conditions helped by fish oils. Fish oils (cod liver oil, krill oil, salmon, etc) have lots of vitamin d which can moderate various psychiatric conditions and omega-3's which reduce "inflamation". Good for the heart, good for the joints, good for the brain. Deficiencies in Vitamin B's can cause neurological problems. (vitamin D and the B complex help each other out) Another trend is the effect of blood sugar and insulin swings. The more stable the better. This is an argument for low-glycemic eating.
So I guess my point is that no single supplement will replace a good diet and an active lifestyle, but it could be a part of a good diet and active lifestyle.
My FIL? Sits, watches golf and eats cookies ... all day.
Another good theory down the drain!! I appreciate your input and know you are correct in your assessment. So many of us are looking for that 'magic bullet' we tend to grasp at straws. Luckily, I will be able to assess pretty quickly whether this stuff works or not, and I'm not out that much if it doesn't. You'll have freepmail in a bit.