We recently went private. Our GP didn't have a clue where to suggest (not sure if they're meant to know?) so we did our own research and asked for recommendations. The GP was very supportive and helpful otherwise though. The NAS helpline was helpful, and actually, I think there is some information on the NAS website about clinics. Some clinics need a gP referral, others do not. We asked for a referral to the Elizabeth Newson Clinic, but were turned down as we couldn't get CCG funding and they weren't accepting private referrals at the time, so we found a recommended paed and psych who had plenty of experience with PDA.