The Brain and Addiction

Through interdisciplinary collaboration, researchers at the University of Copenhagen have created a model of the way the brain releases dopamine. This model will be an important tool in helping scientists better understand how humans learn and how the brain perceives reward. Because of dopamine’s involvement in these activities, the researchers hope that the model can assist in further understanding drug and alcohol addiction and necessary treatment and rehabilitation options.

Dopamine is involved in a number of the brain’s processes that control the way we behave. It plays an important role plays in our ability to handle stress, be motivated, and create an overall sense of well-being. It is a key neurotransmitter in the reward center of the brain.

Certain actions that exceed expectation will cause the brain to temporarily release more dopamine. Actions that are worse than expected will cause the brain to momentarily stop releasing dopamine. This ultimately makes dopamine a “learning signal” that causes us to repeat the actions that give us higher levels of dopamine and avoid those that result in lower dopamine levels. This action also applies to food, sex and competition. The use of drugs and alcohol also raises the level of dopamine.

Some scientists have argued that the dopamine system doesn’t react quick enough to be a part of the human learning process. However, they focused primarily on the slow feedback time when experiencing something negative. Whereas, this new model shows that “the collective signal from many cells provides a rapid enough reaction to influence learning.” (Medical News Today)

The new dopamine model was created in a collaborative effort among physicists, mathematicians and neurobiologists, and its predictions are supported by observations made in animal models. The researches are hoping that it will help overcome some of the challenges faced by neurologists that are often unable to study active brains in living humans. Once the researches are certain the model is correct, then they will begin applying it to dopamine-related illness such as drug and alcohol addiction.

The researchers’ dopamine model will soon be described in the cover article of Journal of Neuroscience.

A small study at the University of California, Los Angeles, found that risk-taking tendencies (and sometimes high-risk activities) in teenagers, including the use of drugs or alcohol, may be largely driven by what scientist refer to as a “hypersensitivity” to the brain’s release of dopamine (a powerful, pleasure/ motivator chemical in the reward center of the brain).

Using three age groups: children ages eight to 12, teenagers 14-19, and adults ages 25-30, the researchers had the volunteers perform reward-incentive tasks while a functional magnetic resonance imaging scanner (fMRI) measured the blood flow in their brains. The tests revealed that the striatal area of the brain, which is sensitive to dopamine, lit up more strongly among the teenagers than the adults or children when receiving a reward.

A lead researcher further explained that the study shows “that when adolescents get a reward that they’re not expecting, their brains are more responsive to that reward.”

This understanding of the adolescent brain is particularly important when understanding how susceptible they may be to drug or alcohol abuse and addiction that directly targets the reward center of the brain. Such knowledge reiterates the need for delaying the use of drugs or alcohol among teens, as well as possible age-specific prevention tactics, early intervention, and rehabilitation.

According to LoveToKnow.com, here are some warning signs of possible alcohol abuse:

• Daily or frequent use of alcohol. “I need a drink to calm me down“ or “There’s nothing like two stiff drinks after a hard day at the office.”
• Solitary drinking. If an individual displays a distinct preference for solitary drinking, especially on a daily or frequent basis, there may be cause for concern.
• Making excuses to drink. If you find someone simply waiting for an excuse to drink, however trivial or frivolous it may seem to others, it is time to start the alarm bells ringing.
• Secretive behavior. Telling lies about their whereabouts, spending large amounts of time away from family, covering up on the amount of drinking–all of these are warning signs.
• Hostility when directly questioned. Substance abusers are often hostile or aggressive when confronted about their drinking.
• Work-related difficulties. Underperforming relative to ones abilities, not getting the job done, problems with professional relationships, not delivering, unexplained absences, and tardiness are often present with alcohol abuse.
• Financial negligence and/or distress.
• Arrest, DUI or other trouble with the law. DUIs, near misses, and accidents are common with alcohol abuse. Fights and other forms of violence are also warning signs.
• Blackouts. Not remembering what happened while drinking is a sign that there is a problem.

 

Researchers at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a new mapping protocol that allows them to visualize the activity of dopamine, the brain’s reward circuitry, in both healthy individuals and those addicted to drugs and alcohol. This new dopamine mapping technique may offer better insight into why people partake in the use of drugs and alcohol as well as determine which treatment protocols may be the most effective.

Using positron emission tomography (PET), which is medical imaging technology used in identifying brain diseases, and radioactive tracers that bind to dopamine receptors. The PET scan highlights the movement of the tracers in the brain. This is then used to reconstruct real-time 3D images of the dopamine system at work. (Medical News Today)

Although it’s understood by the scientific community that drug addiction is a complex process consisting of many biological and environmental factors, it’s clear that the role of dopamine is central to the understanding substance abuse. Dopamine is the chemical that regulates reward and pleasure in the brain. The study found that the addicted individuals had 15-20 percent fewer dopamine receptors than those in the control group (healthy individuals). (Medical News Today)

One of the scientists at Brookhaven explained that individuals suffering from the disease of addiction all have “blunted dopamine response.” This understanding reinforces previous notions that addicts “experience diminished feelings of pleasure, which drives their continual drug [and alcohol] use” and furthers the damage to the reward center of the brain. The study looked at the results of various types of drugs. And although each operated by unique mechanisms, they all shared one thing in common: the dopamine receptors in addicted brains demonstrated an under-stimulated reward system.

Therapies such as Neurotransmitter Restoration (NTR) support the findings of this study in understanding the key role of dopamine in addiction and addiction recovery. NTR is a medical nutritional therapy that bathes the neuronal cells in an optimal, nutritional environment, stimulating dopamine receptors to induce repair and accelerate the brain’s healing process.

Researchers hope that the real-time aspect of the new imaging protocol may prove to be valuable because it doesn’t require looking at individuals while they are under the influence of drugs or alcohol, but rather when they aren’t. This will allow for examining how different coping strategies of rehabilitation and abstinence work best.