What it really gets down to is the individual&#x27;s compsition in a variety of factors (physiology). Each drug has a &#x27;profile&#x27; of how it acts, or at least we categorize them for understanding. Thus, no two people will react the same way to the same drug, and no two drugs will react the same way in the same person, in my experience.<p>Thus, you get somebody like Willie Nelson who is essentially a life-long pot head where his drug use&#x2F;abuse didn&#x27;t get in the way of his work; Willie has also noted that Waylon Jennings was fond of speed, but that Willie didn&#x27;t like the stuff. Going down the list of accomplished writers yields a treasure trove of alcoholics not frequently remembered for the wreckage they made of their lives (F. Scott Fitzgerald, O. Henry, Hemmingway).<p>As a society in the US, the unfortunate moralistic approach to addiction as a personal failure rather than a physiological concern holds back those who could likely benefit from certain substances but never come into contact with them. Also of note, it would seem a certain percentage of the US population simply has an addictive compsition:<p><a href="http:&#x2F;&#x2F;cdn.thewire.com&#x2F;img&#x2F;upload&#x2F;2012&#x2F;10&#x2F;12&#x2F;drug-spending-v-addiction.gif" rel="nofollow">http:&#x2F;&#x2F;cdn.thewire.com&#x2F;img&#x2F;upload&#x2F;2012&#x2F;10&#x2F;12&#x2F;drug-spending-v...</a>