There were times when the caffeine in my morning coffee absolutely caused me to become deeply depressed, but those were times that were filled with personal turmoil and conflict. These days, I seem to be OK with 2 morning cups and a diet soft drink with caffeine during the day. My adult son can't mess with caffeine at all because of blood pressure and heart rate issues.
(I am 100% dependent on my morning coffee....addicted. 😛)