Subtypes of insomnia (IMAGE) Netherlands Institute for Neuroscience - KNAW Caption Subtypes of insomnia. Based on personality traits and mood, people with insomnia can be divided into five subtypes. MRI scans show that these five subtypes also exhibit abnormalities in different parts of the brain, indicating different biological vulnerabilities. Credit Netherlands Institute for Neuroscience Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.