How Much Does A Private ADHD Diagnosis Cost? You may need to go the private route if are an adult suffering from ADHD. This is a good option as private psychiatrists are more experienced in diagnosing people with ADHD. They will also screen for co-morbidities such as anxiety and depression http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=860043