Addiction and the External
I believe there are two ideas Dr. Hart may be implying in drug addiction and the fear of drug addiction. One idea is that people may have a strong feeling that they don't have free will(a lack of of choice - Someone else knows what makes me happy more than I do). Another idea is that people have a fear that others won't and don't accept them (A fear of others not feeling the same way you do in any given situation). I believe drugs as well as communicating with anything external to yourself, are a means of denying or finding a Truth. The irony is that Truth is merely what makes 'you' content. Many dread the idea that the world, as well as themselves, are beyond fixable. The truth is, in this regard, one does not have a choice. You have to strive for a more content self. You have to hope for a better future for there is nothing to loose...
We must make our best guess as to what external to us is good for us.