People who drink moderately may be able to say no to alcohol. They may go days, weeks or years between having a drink. However, someone who struggles with drinking is often unable to act the same way. Instead, they may drink compulsively on a daily basis. When someone is addicted to alcohol, drinking becomes a big part of their life, even if they want to stop. This can lead some people to wonder why people who are susceptible to addiction drink.
A Chemical Imbalance
The neurotransmitters, or brain chemicals, of people who struggle with drinking can differ from other people. Studies have shown that drinking causes a change in the way certain important brain chemicals function. Drinking can cause these chemicals to become imbalanced. In particular, drinking affects:
- Gamma-aminobutyric acid, or GABA: Drinking depresses the central nervous system by increasing the levels of this chemical.
- Glutamate: Drinking suppresses the levels of this chemical, which revs up the central nervous system under normal circumstances. In turn, the central nervous system is further depressed.
- Dopamine: This chemical, part of the brain’s reward system, is triggered by drinking, leading to a feel-good state and desire to keep drinking.
- Serotonin: Drinking increases the level of this chemical, which is linked to a sense of well-being and a good mood.
Over time, the brain becomes used to these chemical imbalances. In turn, a person needs to drink larger amounts more frequently to reach the same state of relaxation and well-being that they once did. As the brain continues to adapt to alcohol, when a person is not drinking, they can start to go through unpleasant symptoms of withdrawal because their brain chemistry has changed.
Alcohol Changes the Brain
Besides changing the levels of brain chemicals, over time, drinking can change the brain itself. The brain then responds differently to the outside world than it normally would. Parts of the brain known to change from long-term drinking include:
- Prefrontal–striatal–limbic circuit: This part of the brain controls emotions, decision-making and stress and can be harmed in long-term drinking.
- Ventral striatum: The feel-good brain chemical dopamine stops working as well in this area of the brain.
- Prefrontal cortex and orbitofrontal cortex: People who struggle with drinking have less gray matter, or brain cells, than normal in this part of the brain responsible for decision-making.
Even when people who struggle with drinking try to stop, having setbacks, or relapses, is common. Without help, it is often easy for many people to go back to the same lifestyle and drinking patterns they had before quitting. The long-term brain changes and chemical imbalances from drinking raise the risk of relapse without help.
Costardi, João Victor; et al. “A review on alcohol: from the central action mechanism to chemical dependency.” Revista da Associacao Medica Brasileira, 2015. Accessed December 29, 2019.
Seo, Dongju. “Neuroplasticity and Predictors of Alcohol Recovery.” Alcohol Research Current Reviews, 2015. Accessed December 29, 2019.