This was certainly the case for me, and more as I had bad reactions to two of the meds and had to swap instantly. Obviously couldn't get a refund. Titration of various meds never resulted in a therapeutic outcome.
I then developed a heart issue as a direct result of methylphenidate and ended up in A&E. I wasn't looked on particularly kindly by the doctors that treated me.
I didn't cope well on any of the medication. In fact, it made me "worse", highly jittery, anxious, mood swings or extremely depressed and paranoid. Eventually the private company became uncontactable,
having taken money in advance for a year of treatment then transfer over to shared care.
They were later on the news for handing out diagnoses willy nilly. When I got my report from them, via my GP, they'd falsified the evidence that was the basis of diagnosis. They'd written things like "was very disruptive in school,
struggles to make and keep friends". When I'd told them over and over that I'd been seen as a model pupil by teachers, and I have a great,
supportive friendship circle and make friends easily.
I now consider the ADHD diagnosis from them to be unsound. I think they just wanted the money. Please be careful. The NHS may take years longer, but they won't steal your money.