As dependence grows, alcoholics also lose the ability to properly regulate their behavior. This regulation is the responsibility of the prefrontal cortex, which is charged with keeping the rest of the brain apprised of the consequences of harmful actions. But mind-altering substances slowly rob the cortex of so-called synaptic plasticity, which makes it harder for neurons to communicate with one another. When this happens, alcoholics become less likely to stop drinking, since their prefrontal cortex cannot effectively warn of the dangers of bad habits.
The loss of synaptic plasticity is thought to be a major reason why more than 90 percent of recovering alcoholics relapse at some point. Because the synapses in their prefrontal cortex are still damaged, they have a tough time resisting the urges created by these triggers. Any small reminder of their former life—the scent of stale beer, the clink of toasting glasses—is enough to knock them off the wagon.
AA, it seems, helps neutralize the power of these sensory cues by whipping the prefrontal cortex back into shape. Publicly revealing one’s deepest flaws and hearing others do likewise forces a person to confront the terrible consequences of their alcoholism—something that is very difficult to do all alone.