Prevalence of mental disorders is greatest in adolescence and early adulthood,1 and adolescents and young adults with type 1 diabetes are an especially vulnerable group.2, 3 Daily self‐care of type 1 diabetes involves complex activities that are often highly intrusive into daily life including monitoring of blood glucose levels and hyperglycaemic and hypoglycaemic symptoms, assessing carbohydrate intake with insulin treatment (multiple injections or infusion from a pump); and meal‐to‐meal adjustment of insulin dose depending on diet and physical activity. The gene discussed is INS; the disease is mental disorder.