This report of the ILAE Child Neuropsychiatry Taskforce, Neuropsychobiology Commission, was published as an e-supplement in Epileptic Disorders (Volume 8, May 2016), educational journal of the International League Against Epilepsy. Psychiatric and behavioural problems are reported to occur in 35-50% of children with epilepsy. They affect the quality of the childrens and their families lives in a very challenging manner. The ad hoc Commissions and Taskforces of the International League Against Epilepsy are regularly following progress made in the field, also promoting a larger diffusion of existing knowledge and future research. The present report is a state-of-the-art critical review, putting together numerous data concerning topics such as epidemiology, pharmacotherapy, the effects of antiepileptic drugs and epilepsy surgery, the relationships between epilepsy and many psychiatric disorders. It also points out the specific areas in need of controlled trials, such as early diagnosis and management. This report was published as an e-supplement in Epileptic Disorders (Volume 8, May 2016), educational journal of the International League Against Epilepsy.