I'm very interested to see if the NHS will pay. They might refer you if they cannot provide the services that you require themselves. In that sense you would probably be unique unless it is for something very specific and you require urgent treatment for it. Let us know how you get on. Years ago this type of referral was called an ECR an extra contractural referral ie your PCT or Health Authority would buy in the services that you require. Such referrals these days for mental health are very rare.