The need to merge child and adult psychiatry into a continuum was discussed based on forensic issues in criminal cases involving developmental disorder. Recently, a number of offenders (both juvenile and adult) are being diagnosed with developmental disorder every year, when the system of sending severe juvenile cases from juvenile court to the prosecution as well as the new juror system makes the role of psychiatric examination more important than ever. Because of the unique symptomatology of autism spectrum disorder (ASD), conventional forensic psychiatry does not seem applicable to cases of ASD when making a fair judgement on criminal liability. This indicates that there is a need for not only basic knowledge on child psychiatry for all psychiatrists, but also knowledge on the developmental link between child and adult psychiatry. Therefore, there is a need to merge child and adult psychiatry into a comprehensive field of developmental psychiatry.
 <Author's abstract>