 Extreme premature birth , very low birth weight , and extreme neglect , abuse , or social deprivation also increase the risk as do certain infections during pregnancy , at birth , and in early childhood . These infections include , among others , various viruses ( measles , varicella zoster encephalitis , rubella , enterovirus 71 ) . At least 30 % of children with a traumatic brain injury later develop ADHD and about 5 % of cases are due to brain damage . 
