Addiction is a disease that has been linked to genetics, but the environment also plays a role in addiction. Factors like chronic stress and poor social support can cause changes in the brain, resulting in an increased risk of addiction. Substances, both legal and illicit, also affect the brain’s reward centers.
Most people can stop using drugs like caffeine with few side effects, and the side effects that are experienced are usually mild and short-lived. Addiction is characterized by the desire to use drugs, even when using drugs negatively affects their life. Addiction can cause people to choose drugs over their friends and family, and financial ruin is a common side effect of long-term chemical dependencies.
With all of the negative side effects that are linked to addiction, it is easy to wonder how using drugs triggers the brain’s reward center. The simple answer is dopamine, a hormone that triggers feelings of pleasure when it is released by the reward center.
When the reward center is activated by drugs and alcohol, the person experiences intense feelings of pleasure, called euphoria. Euphoria occurs when the substance triggers the release dopamine by directly affecting the reward center.
Activating the Reward Center
Although dopamine is traditionally called the pleasure hormone, it also plays a role in addiction by affecting how focused we become on the things we want. The release of dopamine does trigger the euphoric high typically associated with substance use, but the hormone is also linked to the focused desire for things that trigger its release. Anytime you become so focused on something that everything else becomes unimportant background noise, you are experiencing the effects of your brain’s reaction to the release of dopamine.
In studies on reward mechanisms, scientists found that test subjects were willing to endure negative experiences to trigger the reward centers. Although the brain naturally releases dopamine to trigger feelings of pleasure, the feelings of euphoria experienced when substances activate the reward center are often much stronger.
Triggering Dopamine Release
Substances like methamphetamine and cocaine release significantly more dopamine than the brain naturally releases during a pleasant experience. In people who are predisposed to addiction, the euphoric feelings caused by dopamine release often results chronic substance use. For a while, the person experiences the expected high, but usually needs more of the substance to feel the expected effects.
Tolerance develops when someone uses a substance long enough for a physical dependency to develop. Chronic drug users often feel normal only when they use the substance because their brain chemistry has altered in response to the continued presence of drugs or alcohol. These physical changes in the brain are partially responsible for withdrawal symptoms that occur when someone with a chemical dependency stops using drugs.
In an effort to avoid the pain of withdrawal symptoms, overwhelming cravings occur when someone with an addiction tries to stop using drugs. The withdrawal symptoms and cravings only appear after a habit-forming addiction is well-established, however. Addiction is usually a gradual process that appears with repeated substance use, and repeated substance may be linked to the strong influence of the brain’s reward system and the desire to experience the rush of dopamine released by using drugs.