PM (by his appointee) v The Secretary of State for Work and Pensions

An appeal concerning entitlement to the higher-rate mobility component of Disability Living Allowance through the severe mental impairment route should not be decided on an asserted state of current medical opinion without an adequate evidential basis. Where relevant medical evidence may establish that ADHD results from arrested or incomplete physical development of the brain, a tribunal must explain its contrary medical finding. In an inquisitorial jurisdiction, it may also be an error of law to decide the appeal without seeking specialist evidence where that evidence could materially affect the outcome. The statutory test remains cumulative: satisfying the brain-development limb of regulation 12(5) does not itself establish severe impairment of intelligence and social functioning or the severe behavioural problems required by regulation 12(6).

The appellant appealed against a decision of the First-tier Tribunal dated 26 September 2023, which dismissed his appeal against the Secretary of State’s decision on his Disability Living Allowance entitlement. The First-tier Tribunal accepted the other elements of the severe mental impairment route but concluded that ADHD did not arise from arrested or incomplete physical development of the brain under regulation 12(5) of the Social Security (Disability Living Allowance) Regulations 1991.

Permission was granted on the question whether ADHD might constitute arrested or incomplete development of the brain. During the Upper Tribunal appeal, the Secretary of State obtained specialist evidence which supported that conclusion and accepted that the appellant satisfied the relevant criteria. The central issues were whether the First-tier Tribunal had made a material error of law on the evidence available at the time, and whether the appeal should be remade.

1. The appeal was allowed. The First-tier Tribunal’s decision was set aside under section 12(2)(a) and (b)(ii) of the Tribunals, Courts and Enforcement Act 2007, and the appeal was redecided.

2. The Upper Tribunal emphasised that a later expert report, or a party’s later acceptance of its conclusions, does not by itself demonstrate an error of law in the First-tier Tribunal’s decision. The question was whether the First-tier Tribunal had erred materially on the evidence before it when it decided the case in September 2023.

3. The First-tier Tribunal had failed to give an adequate explanation for its conclusion that current medical opinion did not support ADHD being caused by arrested or incomplete physical development of the brain. The specialist report identified substantial medical literature supporting that conclusion, including the 2017 and 2020 reports considered in the appeal. The evidential deficiency was material because the finding was dispositive of the appellant’s claim under the severe mental impairment route.

4. Alternatively, the First-tier Tribunal had erred by failing to consider an adjournment to obtain specialist evidence. Its reasoning suggested that specialist and technical evidence could have affected the outcome. The tribunal was also aware from CS v SSWP (DLA), UT file reference UA-2021-SCO-000005-DLA, that specialist evidence had been obtained in a similar case. In those circumstances, the inquisitorial function required consideration of obtaining such evidence.

5. The Upper Tribunal stated that SC v SSWP [2010] UKUT 76 (AAC) was wrongly decided and that NMcM v SSWP (DLA) [2014] UKUT 312 (AAC) stated the proper legal approach to regulation 12(5), although nothing turned on that issue for the appeal.

6. On remaking the decision, the Upper Tribunal accepted the specialist evidence that the appellant suffered from arrested or incomplete physical development of the brain. The remaining findings under regulation 12(5) and (6) were favourable and unchallenged. The Secretary of State’s decision was therefore set aside, and the appellant was held entitled to the higher-rate mobility component and highest-rate care component of Disability Living Allowance from 27 January 2021 to 9 August 2026.

• First-tier Tribunal (Social Entitlement Chamber): On 26 September 2023, dismissed the appellant’s appeal, holding that ADHD did not satisfy regulation 12(5) of the Social Security (Disability Living Allowance) Regulations 1991.
• Upper Tribunal (Administrative Appeals Chamber): Allowed the appeal, set aside the First-tier Tribunal’s decision for material errors of law, and remade the decision in the appellant’s favour.