Services for adults with suspected ADHD have very long waits both locally and nationally.
Your GP may not be able to enter into “shared care” arrangements with online/remote/other providers for adult ADHD care, and therefore may not recommend an NHS referral to these providers. Or they may be able to refer to alternative providers “for assessment/diagnosis only”, but not able to share care for treatment. They may recommend that a referral to the local provider is in your best interests, even though the waiting list is long.
Your GP may suggest a referral to the private sector, but would not be expected to enter into “shared care” with private specialists, as the NHS GP.
This is a “commissioning gap” – where the services available on the NHS do not meet the needs of the population – and it has been raised locally and nationally.
You may wish to raise it yourself, e.g. with your MP and/or with the ICB.