Louise Arseneault, Professor of Developmental Psychology at Kings’ College London, is a world leader in the study of the development of mental health problems. The impact of her work on policy and practice is impressive: Her research on cannabis use as a potential cause for the development of schizophrenia informed politicians and policy makers when the British government prepared to declassify cannabis to a less harmful drug. Her more recent work contributed to claims that victimisation by bullies should be considered as a form of childhood abuse. Professor Arseneault translates scientific evidence to the general public and her findings generate great media interest.