It's like this. Do you know why most small animals live shorter lives? One of the reasons is a faster heart beat. When you take drugs to make things go up a notch you are speeding up your heart which means you will live a shorter life. Although drugs were/are used in some primitive folk cultures for vision quests and magic, the only reason you should be taking drugs is obtain equilibrium. If you want to get high (dopamine), there are other ways to get high besides drugs. Natural ways. Exercise. Sex. Adrenalin rush from activities. Etcetera.