1. Introduction. PART ONE: DRUGS AND THE BRAIN. 2. Neurotransmitters: The Brain's Own Drugs. 3. Receptors: Locks for the Addictive Keys. 4. Addictive Behavior. 5. Pain and Pleasure. 6. The Seesaw Brain: "Highs" and Adaptations. 7. Are Addicts Born or Made?. PART TWO: DRUGS AND T…