The threat comes after The Guardian reported West Yorkshire ICB was one of four ICBs to impose two-year minimum waits.

Henry Shelford, the chief executive of ADHD UK, told HM: ‘It's the National Health Service, not the regional health service. We strongly consider West Yorkshire ICB's action to lock their patients out of wider NHS care to be fundamentally wrong, and we are challenging them on their decision to do so and the process by which they did it.'

West Yorkshire ICB said the two-year minimum waits were part of a ‘wider programme to improve equity, quality and long-term outcomes'.

The ICB said people can be assessed sooner in the event of significant safety, physical health, mental health or education risks, adding ‘people awaiting medication and ongoing safe monitoring will also continue to be prioritised'.

‘We are investing £29.7m in neurodevelopmental services in 2026/27 – more than £4m above the previous year – to strengthen the support available to local people,' a spokesperson said.

The ICB added it was developing neurodiversity hubs to offer a ‘clearer, more joined-up route to support, with a single point of access, structured triage and help based on individual needs across community, education, mental health and social care'.

It further commented: ‘Our aim is to help people receive the right support as early as possible, whether or not they go on to have a diagnostic assessment. This will reduce reliance on diagnosis as the only route to help and support earlier intervention, helping to reduce the risk of crisis.'

The ICB said it would review its approach to waiting times as part of planning for 2027/28.

Addressing, the legal threat from ADHD, the ICB said: ‘We have received correspondence from ADHD UK. As this matter may be subject to legal proceedings, it would not be appropriate to comment further at this stage.'