The Neurobiology Of Addiction

Addiction occurs at many different stages of human life. The most common and well-known addiction is drug addiction. You may define drug addiction as compulsive behavior when addicts seek and use drugs, lose control over its restriction, and have a negative state of mind if they do not receive drugs. Most people are pretty familiar with the properties of drug addiction. But what is the neurobiology of addiction?

Some experts define addiction as a spiral with three stages: binge drinking / intoxication, sobriety / negative emotions, and anxiety / anticipation (anxiety). The last stage worsens over time and causes neuroplastic changes in the brain’s reward center as well as stress and specific functioning systems. (2-4)

Impulsivity “includes the ability to react immediately and without planning to internal and external stimuli without taking into account at all their negative consequences for the individual or others” (5). Compulsive behavior, on the other hand, “consists of repetitive acts characterized by a feeling that a person“ must ”do so, even though he or she knows that these acts are not in line with his or her overall goal” (6).

People with addiction thus move from impulsivity to compulsion. These two stages may also occur simultaneously, but usually they come in this order. Likewise, the brain functions in a certain way in both of these stages.

The neurobiology of addiction during intoxication

Remuneration system

Addictive drugs activate the brain’s reward system.  One of the main focus of neurobiology and the pleasurable effect of drugs is the origin and regions of the mesocortical pathway. They are responsible for the pleasing properties of almost all drugs.

Drug or alcohol intoxication appears to release dopamine and peptide opioids in the ventral brainstem. The rapid and clear release of dopamine is also largely related to how people feel when under the influence of drugs. (1)

Incentives

In some studies, researchers have found that dopamine cells in the brain initially respond to a new reward. However, after repeated exposure to the reward, the neurons cease to respond when the predicted reward was obtained.

Instead, they react when exposed to stimuli that anticipate reward. Thus, it appears that dopamine has a close relationship with how the brain seeks reward.

The neurobiology of addiction during the anticipatory phase

Researchers believe that this step is key to the person collapsing again.

However, addiction is a chronic recurrence disorder. People’s desire to use drugs is related to the activation of the forebrain, which includes:

• Dorsolateral forebrain block
• Front pliers
• Medial orbitofrontal cortex

Cocaine or nicotine dependence is also associated with brain island function. This area of ​​the brain appears to be a challenging function that connects autonomous and visceral knowledge with emotion and motivation. In fact, studies show that brain island reactivity is a biological marker that can help predict recurrence.

Finally, during this phase, the researchers believe it involves two opposing systems: a start system and a stop system.

Start and stop system

The trigger system may cause cravings and engagement through the nucleus accumbens. For example, cocaine craving for a cocaine-dependent person is associated with a better connection in a network connecting the medial forebrain and anterior forceps in the ventral brainstem and in a network connecting the brain island to the dorsal brainstem.

The stopping system can control the evaluation of the value of the stimulus as well as the options and suppression of the mental response to negative mental signs. In this system, a stop system would prevent the start system and the drug craving system.

In summary, therefore, the neurobiology of addiction consists of three main stages. They react to the performer of their main part: the root nucleus, the tonsil nucleus, and the forebrain block.