Chapter 8 begins with Knapp noting how heavy, chronic drinking can damage virtually every organ in the human body. She notes how alcoholism is the leading cause of liver disease in the United States and increases the risk of cancer, cardiovascular disease, sexual dysfunction, infertility, and many other medical problems. Alcohol and violence are also linked. Experts estimate that it’s a factor in nearly half of all homicides and a third of all suicides. For these reasons, Knapp likens her love affair with drinking to playing with fire.

Knapp says the body of a normal drinker tells that normal drinker when it’s time to stop consuming alcohol. Such a drinker will usually stop drinking before alcohol begins to slur their speech or delay their reflexes in a noticeable way. People with alcoholism have a different physical makeup, she explains. Alcoholism most likely has a strong genetic component, as it tends to run in families. Brain molecules get altered when exposed to alcohol repeatedly, and this seems to cause problems for the brain’s reward system. Alcohol activates this system artificially. The neurotransmitters and proteins that create feelings of well-being change, and the brain loses its ability to create feelings of well-being without alcohol.