The actual study is here: https://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society/article/anomalous-brain-development-is

The actual study is here: https://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society/article/anomalous-brain-development-is-evident-in-preschoolers-with-attentiondeficithyperactivity-disorder/BDC2EAEA1039EADFEDA9E1980046BB6C https://www.cambridge.org/core/journals/journal-of-the-inter... This study is primarily new because it examined preschoolers. Most studies that have previously shown structural brain differences are of school aged children.