ADHD Assessment - Why it's Important to Get a Private ADHD Diagnosis Anyone who suspects they have ADHD but has not been diagnosed should get an ADHD assessment. The process could take up to two hours, and it is recommended to bring an adult family member or a friend along. https://private-adhd-assessment03455.thenerdsblog.com/35383227/adhd-diagnosis-uk-private-11-thing-you-re-leaving-out