Addictions focus on alterations in the brain's mesolimbic dopamine pathway, also known as the reward circuit, which begins in the ventral tegmental area (VTA) above the brain stem. Substance use disorders result from changes in the brain that can occur with repeated use of alcohol or drugs. The most serious expression of the disorder, addiction, is associated with changes in the function of brain circuits involved in pleasure (the reward system), learning, stress, decision-making and self-control. addiction affects the brain on many levels.
Chemical compounds in stimulants, nicotine, opioids, alcohol and sedatives enter the brain and bloodstream after use. Once a chemical enters the brain, it can cause people to lose control of their impulses or want to consume a harmful substance. After repeated drug use, the brain begins to adapt to dopamine surges. Neurons may begin to reduce the number of dopamine receptors or simply produce less dopamine.
The result is less dopamine signaling in the brain, such as lowering the volume of the dopamine signal. Because some drugs are toxic, some neurons can also die. Alcohol and drugs affect neurotransmitters and neural pathways in the brain. At the same time, the brain struggles to maintain balance.
As a result, when drugs and alcohol change brain chemistry, the brain adapts. Once adaptation becomes the norm, the brain will want to “correct an imbalance” when the drug is no longer present by taking the drug again. Over time, substance use disorder changes both the structure of the brain and its functioning. For example, the brain will reduce dopamine production if a drug artificially recreates the effects of dopamine.
Over time, substance use disorder (SUD) changes both the structure of the brain and how it works. These images show how scientists can use imaging technology to measure brain and heart function. The highest activity is shown in the reds and yellows, and the reduced activity is shown in the blue and purple ones. Both the healthy brain and the healthy heart show greater activity than the diseased brain and heart, because both addiction and heart disease cause changes in function.
In drug addiction, the frontal cortex, in particular, shows less activity. This is the part of the brain associated with judgment and decision-making (NIDA). Addiction is a complex disease that affects brain function. The part of the brain that causes addiction is called the mesolimbic dopamine pathway.
Sometimes called the brain reward circuit. Let's take a deeper look at the causes of addiction and how this area of the brain is affected. However, due to its delicate structure and chemistry, the brain is also very vulnerable to addiction. Drugs and addictive behaviors are a shortcut, flooding the brain with dopamine and other neurotransmitters.
They can discover how to improve brain activity, reducing the effects of addiction and unhealthy impulses. They thought that overcoming addiction involved punishing evildoers or, alternatively, encouraging them to muster the will to break a habit. These may include avoiding people, places, and situations associated with addictive behavior, as well as finding new ways to manage disturbing or difficult emotions or life circumstances. People who develop an addiction often find that, over time, the desired substance no longer gives them so much pleasure.
Conditioned learning helps explain why people who develop an addiction are at risk of relapse even after years of abstinence. Fortunately, researchers have found that brains that have been damaged by addiction have the potential to “unlearn addictive behaviors”, although the risk of addiction never magically disappears. Using technologies such as magnetic resonance imaging (MRI) and positron emission tomography (PET), medical professionals can see inside the inner workings of the brain, both in an addictive state and without. A challenging problem in the neurobiology of drug addiction is understanding why some people become addicted to drugs while others don't.
Scientists once believed that the experience of pleasure alone was enough to entice people to continue searching for an addictive substance or activity. In addition, a recent imaging study reported structural changes in the OFC of subjects addicted to cocaine (5), and the possibility that this could have preceded drug use and could have made these subjects more vulnerable to addiction was discussed. An important sign of addiction is that a person continues to use drugs even though this is harming his life. The pleasure associated with a drug or addictive behavior decreases, and yet the memory of the desired effect and the need to recreate it (desire) persists.
As the National Geographic article “The Addicted Brain” states, “Addiction reshapes neural circuits to assign supreme value to cocaine, heroin or gin, at the expense of other interests such as health, work, family or life itself. . .