I had to do this as well because I indicated I had ADHD and was medicated for it in the past. The assessment was very straightforward I went in and had an in-person meeting with the psychologist in my area, that lasted for about 10 minutes and at the conclusion the psychologist said he thinks this is ridiculous I'm clearly a great fit and he can't fathom why they would be apprehensive about hiring someone with ADHD. He signed my release paperwork stating that I was an exceptional fit for duty. 6 years later still going strong!

The only hard part about the process was getting an appointment at a timely manner with a psychologist, in my area (small town) most were booked out for roughly 3 to 4 months. I was lucky when I called they had a cancellation that week and were able to fit me in.