We’ve always understood that some of these things are out of a person’s range of control, however a recent study has determined that in addition to genetics and environment, a person’s brain size can influence addiction risk. While there is currently no direct correlation between brain volume and intelligence, research and clinical experiences have proven that anything below normal brain volume can diminish the brain's functional capacity.
Decreased brain volume in certain brain areas has also been linked to Alzheimer's disease, schizophrenia, and other types of dementia. The process of substance addiction affects the area of the brain known as the pleasure center, where the chemical dopamine is stored and released. When an individual uses an addictive substance, the amount of dopamine processed through the brain is altered. Since the brain uses dopamine to trigger rewarding sensations, this can cause physical dependence. It can also lead to alteration of the size and shape of the brain.
Researchers from five German and two Chinese institutions conducted a study that was published in Brain: A Journal of Neurology in May 2015. They used results from two projects involving a total of 66 adults, who were non-habitual users of amphetamine or MDMA, who had used the drug 10 times or less. The researchers were looking for a connection between sizes of specific brain structures and whether they had an impact on drug/alcohol addiction. In the first project, brain volumes of 38 participants were assessed at the beginning of the study, as well as one year later. For the second study, researchers did the same assessments for the remaining 28 participants.
Following both projects, researchers found that consumers who continued to use amphetamine or MDMA over time experienced a considerable decline in brain volume, specifically in the amygdala and prefrontal cortex. As we know, the altered output of dopamine could have an effect on physical dependence. But as a result of this study, its authors believe that because the aforementioned brain areas have decreased in size, drug use could increase the reward while concurrently decreasing the user's ability to make conscious decisions regarding their drug use. In addition, the reduced brain volume could be responsible for magnified patterns of drug use, ultimately resulting in addiction.
This is a massive breakthrough in how we understand addiction as it relates to brain function and internal biological mechanisms. After a certain point, addiction stops being a matter of choice and starts becoming a mental health concern, where the diminishing mass of the prefrontal cortex makes it more difficult for a person to consciously exert the will to alter their behavior, especially in regards to an addiction that chases more dopamine to sate the desires of the brain’s pleasure centers.
If you think you or someone you know could be suffering from, or at risk of developing a drug or alcohol addiction, please contact our addiction staff for further assistance and treatment options.