Photograph of a sculpture by British Artist Penny Hardy depicting boy contemplating nature around him.

The aetiology of Tourette syndrome is highly complex and still poorly understood. In this issue, using data from a large, prospective, population-based cohort of children, Mathews et al examine associations of pre- and perinatal exposures with Tourette syndrome and other chronic tic disorders. Their work illustrates the importance of environmental factors in the aetiology of neuropsychiatric co...