Bolhuis K, Lang U, Gyllenberg D, et al. - Researchers assumed the reverse order relationship would also be true (ie, self-harm would predict psychotic/bipolar disorder) considering that individuals diagnosed with psychotic and bipolar disorder are at high risk of self-harm. A prospective register-based study was conducted including everyone born in Finland in 1987, followed until age 28 years (N = 59 476). All hospital records of self-harm presentations, as well as all ICD-10 healthcare registrations of the first diagnosis of psychotic and bipolar disorders, were identified. The relationship between self-harm and psychotic/bipolar disorders was assessed by using Cox proportional hazards models. This study’s findings demonstrate that young people who present to the hospital with self-harm are at high risk of future psychotic and bipolar disorders. Moreover, they represent an important cohort for the prevention of serious mental illness.