Addiction and the Brain

It is frequently said that addiction occurs when drugs “hijack” the brain. It’s hard to nail down what that means, but it does rightly suggest that there is an involuntary takeover of the brain that compromises decision-making and diminishes freedom of choice, making quitting difficult even in the face of desire to do so. What happens in addiction is that, through completely natural processes involved in all learning, the brain prunes nerve pathways of attention and motivation to preferentially notice, focus on, desire, and seek the substance. What starts out as a choice becomes, in a sense, a prison.

Because substances of abuse act directly on the reward center of the brain to deliver their high—this involves speedy and intense release of the neurotransmitter dopamine—addiction can be seen as a shortcut to reward, one that, over time, can have a high cost to physical and mental health. Nevertheless, the outsize sensation of reward makes a powerful case for repetition. And through pathways of nerve connection to other areas of the brain, the response weakens activity of the brain’s decision-making center in the prefrontal cortex.

Overcoming addiction usually entails not just stopping use of a substance but also discovering or rediscovering meaningful activities and goals, the pursuit of which provide the brain with rewards more naturally (and more gradually). And because they require effort, they contribute to growth of many facets of personality and personhood.