ADHD Assessment - Why It's Better to Get a Private One Instead of Waiting on the NHS The NHS offers a private ADHD evaluation however, the wait can be long. Some people have reported waiting for up to three years. GPs can refer patients to private clinics or prescribe medication https://ukpsychiatry76016.dbblog.net/3127860/the-reasons-adhd-assessment-private-is-everywhere-this-year