Facts To Know!! More common in preschoolers and early school years. Untreated behaviour disorders may lead to severe unhealthy behaviours such as addiction, bullying Permissive parenting is highly correlated with a behaviour disorder More than 4 million children are diagnosed with some or the other behavioural disorder One out of three children with anxiety disorder have behavioural disorder Behavioural Disorders Watch short video introduction on what Behavioural Disorders looks like.