This is something I don't see discussed very much... in spite of it being the most widely used drug around the planet. When looking up long-term effects of Caffeine, almost all of the articles I see are related to the negative side effects, addiction, withdrawal, etc.
While it does make sense some negative effects can be felt when abruptly stopping long-term use, I firmly believe long-term, beneficial psychological changes can be caused by caffeine usage. I mean, it is only logical, if a drug is in your system causing your brain to function differently for a long-term period, then those neuronal pathways are going to face plastic changes that induce some degree of Long-Term Potentiation.
Here is a real life example that comes to mind. I have a friend who has always had a TON of energy, since I have known him. He literally has not a drop of anxiety or social insecurity, and is practically afraid of nothing. He is also highly energized it seems. He told me when he was a child, his parents would always have a pot of coffee brewing, and that he had been drinking pure columbian coffee since he was 7 years old, up to several cups a day. What I observe in him is, it seems as if the effects of caffeine are ingrained in his personality. It would also be a perfect example of my theory in the above paragraph. He was on coffee so much that it became natural for his brain to operate in that state.
Now, when you look at the negative effects of long-term caffeine consumption, such as withdrawal and addiction, you have to wonder how the body might recover from those. The body is fairly good at adjusting to operate under stress. If the brain has become used to operating in a "higher gear" as a result of caffeine consumption, then what would be the quickest way it might recover from withdrawal symptoms? A person might be low on energy and antsy for a while after stopping, which is because the body is trying to operate in a higher gear without caffeine aiding it. So instead of shifting permanently back into a "lower gear" the body will begin to compensate by gradually producing more of the chemicals needed to operate in that higher gear..... thus... LTP.
I had always tried to avoid long-term caffeine use, but after a recollection of an experience in high school, I decided to experiment again. 200mg Caffeine Anhydrous pills every day for 2 weeks straight. I then stopped for a few days, and during those few days, while I felt slight withdrawal symtpoms that I gradually recovered from, I felt as if I maintained the psychological enhancement from the Caffeine.
To give more credence to this theory, one can look at various long-term users of heavy drugs, such as Crystal Meth, Cocaine, Heroin, etc. Even after these people have stopped use of these drugs and managed to recover from the withdrawals and what not, they still often demonstrate psychological aspects that may have been caused by those drugs. I know a guy who had a problem with crystal meth, he used to be a very shy person... now even since he has stopped use, he still carries with him this sort of fearlessness-apathy that was caused by his drug use. He claims to me that while the drug made his life shit for a while, it also helped him keep a potentially beneficial psychological state for later in life. Though I do NOT recommend anyone go off and use hard-core drugs for these reasons.
It has been said before, and I'll say it again, Caffeine is the number one most underrated nootropic drug.
