PhD defence O.D. (Olga) Boer

Below is a brief summary of the dissertation:

Many teenagers try alcohol, tobacco, or weed as they grow up. But the teenage years are also a time when the brain is still developing in important ways. Scientists have long wondered: do these substances affect how the brain develops, or does the way the brain develops make some teens more likely to start using them? This dissertation explores that question through seven studies, using brain scans (MRI) to look at brain structure and brain recordings (EEG) to study brain activity. The research is mostly based on data from the large population-based Generation R study. The findings suggest that both directions are true: First, a systematic review and two empirical studies show that some teens may have pre-existing brain differences that make them more likely to use substances. However, these differences vary a lot between studies, meaning we can’t (yet) look at a brain scan and identify any risk for substance use problems. Next, with a review of over 100 studies, we show that starting to use substances in the teenage years is often linked to long-term changes in brain structure. Furthermore, one of our EEG studies showed that alcohol use is connected to how the brain processes mistakes. Finally, the dissertation highlights a promising future for using large-scale EEG data to explore the link between the brain and substance use. With EEG data from over 3000 people, this project offers one of the largest opportunities to date to explore this question in the general population.