On shopping, addiction & blaming dopamine.

Dopamine is a neurotransmitter, a chemical used to carry messages between brain cells.

"Much of the joy of holiday shopping can be traced to the brain chemical dopamine. Dopamine plays a crucial role in our mental and physical health. The brains of people with Parkinson's disease, for instance, contain almost no dopamine. Dopamine also plays a role in drug use and other addictive behaviors. Dopamine is associated with feelings of pleasure and satisfaction, and it's released when we experience something new, exciting or challenging. And for many people, shopping is all those things."
Why shopping makes you feel so good, Tara Parker-Pope, The Wall Street Journal

"No one knows what causes addictive behaviors, like shopping, alcoholism, drug abuse, and gambling," says Ruth Engs, EdD, a professor of applied health science at Indiana University. "Some of the new evidence suggests that some people, maybe 10%-15%, may have a genetic predisposition to an addictive behavior, coupled with an environment in which the particular behavior is triggered, but no one really knows why."

While the origin of addictions remains uncertain, why addicts continue their destructive behaviors is better understood.

"Individuals will get some kind of high from an addictive behavior like shopping," says Engs. "Meaning that endorphins and dopamine, naturally occurring opiate receptor sites in the brain, get switched on, and the person feels good, and if it feels good they are more likely to do it -- it's reinforced." Shopping Spree, or Addiction?