ADHD Assessment - Why it's Important to Get a Private ADHD Diagnosis Getting an ADHD assessment is important for anyone who suspects that they might have undiagnosed ADHD. The process could take up to two hours, and it is recommended to bring a family member or acquaintance along. The evaluation will also include a discussion of the history of mental health and family history. If you reside in England, you can request your GP to conduct an ADHD assessment through Right to Choose. The Psych...