As someone formally diagnosed with one of these mental illnesses, I can confidently say that coffee triggers a beneficial reaction to my illness as well as to other health-adjoint mechanisms in my body. To me, drinking coffee is like breathing air or eating food, and to go without it means symptom flare-ups.

Coffee's great. In the early morning, just the thought of a large cup of steaming black gets me out of bed with pep in my step. A cup of coffee or two in the afternoon always kicks the doldrums away.

Before the grumpy start making noise, yes, I absolutely am addicted. If I miss two days, then I get a headache for three days. Still definitely worth it. Everybody should drink coffee.

Sounds more like dependence/addiction to me

Is it the coffee or caffeine in coffee? Do you feel the same benefits if you have decaffeinated coffee? Can you replace it with just caffeine pills to get same effect?