ADHD Assessment - Why it's Important to Get a Private ADHD Diagnosis Anyone who suspects they be suffering from ADHD but hasn't been diagnosed with it should undergo an ADHD assessment. The process could take up to 2 sessions. It is suggested to bring along a friend or family member. https://edwincedzu.blogolenta.com/26135674/the-history-of-adhd-diagnosis-private-in-10-milestones