I usually go months without caffeine and then get started on it again and use it for a few more months, back and forth.
I never really notice problems one way or the other on it.
due to a heart condition, my dad was told to keep drinking coffee and it is shown that its regulation of dopamine helps prevent alzheimer's (sp?) and parkinson's (sp?) - and a recent study showed that regular coffee drinkers were some crazy amount less likely to kill themselves - again, all related to the effect on the mood regulating neurotrainsmitter dopamine.