Karen Ersche is a Fellow of Clare Hall, and a Professor of Addiction Neuroscience at the Department of Psychiatry. In the field of addiction, she is especially fascinated and encouraged by the way that advances in behavioural and clinical neuroscience have influenced the very concept of addiction, transforming it from what was previously considered a ‘personality’ problem to what is now more widely acknowledged as a brain disorder.

The article by Niamh Jiménez explores the science behind cocaine addiction, particularly in Ireland where a recent National Drug and Alcohol Survey (NDAS) reveals that the country has the highest cocaine usage in the European Union. Though cocaine usage is rising, a notable observation is that only about twenty percent of users develop an addiction.

Professor Ersche shares that there are various risk factors that increase an individual’s vulnerability to future addiction.

“We tend to blame the drug itself, but simply being exposed to the addictive substance isn’t enough to trigger addiction,” she says. “Starting to use cocaine early in life, especially during brain development, increases the risk. Early exposure to a gateway drug or the presence of comorbid disorders is also problematic.”

Other stressors, such as anxiety and depression, poverty, domestic violence, or bullying can also increase the risk of developing an addiction. This is not necessarily due to the stressors themselves, but rather the resorting to poor coping mechanisms.

Professor Ersche highlighted that one factor to consider is a person’s family history, which may in part be influenced by socioeconomic factors but also by genetics;  having a family history of addiction can increase the risk of addiction by eightfold. Although ‘the addiction gene’ has not yet been found, recent research suggest that a gene called SLC6A2 may also play a role in the development of cocaine addiction. This gene encodes a protein known as the noradrenaline transporter, involved in regulating attention and self-control. Ersche and colleagues have discovered that a natural variation of this gene produces an impairment in self-control and a higher risk of developing cocaine addiction.

Though genes may set the stage, addiction demands repeated exposure to the drug leading to lasting changes in the brain. Such changes impair the vital processes of learning, attention, and memory, in ways that serve to reinforce the addiction-like behaviour at all costs. Addiction, from this perspective, has very little to do with willpower and almost everything to do with the intricacies of brain chemistry.

Read more about Professor Ersche and her research here.