How Addiction Develops
The primary directive of your mind and body is survival, and it will go through some interesting adaptations to survive. When you indulge in too much of these hyper-stimulators—be it cocaine, sugar, alcohol, or sex—your brain's reward center notes that you're overstimulated, which the brain perceives as not good for your survival, and so it compensates by decreasing your sense of pleasure and reward.
It does this by downregulating your D2 receptors, basically eliminating some of them. But this survival strategy creates another problem, because now you don't feel anywhere near the pleasure and reward you once had when you began your addiction, no matter whether it's food or drugs. As a result, you develop tolerance which means that you want more and more of your fix but never achieve the same "high" you once had. There's no period at the end of the sentence. And, all the while, the addictive cravings grow stronger.
"Dr. Volkow, through her extraordinary work...showed that the reason why people who have addiction continue with their addiction has very little to do with the pleasure or reward they're getting out of it; it has to do with the pain and the angst of withdrawal, and they don't want that," Dr. Peeke says.
Dr. Volkow's work revealed that the changes taking place in the brains of drug addicts are identical to those occurring in people addicted to food. Regardless of the source of the addiction, you see very little dopamine bonding with its D2 receptors in the brain, as their numbers have been drastically decreased due to continued exposure to the addictive substance/process.
"In the normal brain's PET scan of the reward center, you see a beautiful red-orange because it's all lit up where the dopamine is bonding with the D2 receptors. You show them a sunset or something pleasurable, and you can see beautiful binding going on. What do you see in the addictive brain? Not a whole lot; almost no orange there. For that matter, those D2 receptors are so low in number that these people are in angst. They crave more and more and more of whatever that fix is.
What Dr. Volkow's study was able to show was: 1) food addiction is real and 2) that the changes that take place in the brain's reward center are identical across the board for all addiction. It doesn't matter what the addiction is so long as it's truly an addiction and it meets criteria. This is huge. She also showed that 3) the reward center is just one brain center that is affected. The other one is the frontal cortex, right behind the forehead.
That means you have an impairment of the 'CEO of the brain' in its ability to rein in impulsivity, irritability, impatience, and all of the things associated with withdrawal and addiction. You can't stay vigilant. It's hard to pay attention. You can't be mindful. You can't plan, organize, or strategize. Basically, you're out of control. Now, you have an out-of-control CEO of the brain and you've got a hijacked reward center. What you have, is a full-on addiction."
Early Trauma 'Primes' Your Brain for Future Addiction
Experiencing abuse (e.g. physical, emotional, sexual), neglect, or other trauma during the formative years of childhood, adolescence and young adulthood can significantly affect your frontal cortex, thereby making you more susceptible to addiction. Dr. Susan Mason at Harvard University, working with the Nurses' Health Study II, showed that women who had the highest levels of abuse during childhood had a 90 percent increased incidence of food addiction. In her book, Dr. Peeke also talks about the role of epigenetics, noting there's a "sweet spot" between the ages of eight and 13 when your genome is particularly vulnerable to epigenetic influence.