The IMAGEN study is a large‐scale, longitudinal, imaging genetic study that combines brain imaging, genetics, and psychiatry to increase our understanding of adolescent brain development and behaviour – namely, sensitivity to rewards, impulsivity, and emotional processing. Research teams from London, Nottingham, Dublin, Paris, Berlin, Hamburg, Mannheim and Dresden have been following 2,000 young people and their parents from the age of 14, collecting data from brain imaging, cognitive and behavioural assessments, questionnaires and blood sampling.