Self-diagnosis, ADHD and mental health at work: a growing challenge for UK employers

Self-diagnosis, ADHD and mental health at work: a growing challenge for UK employers

How should employers respond when employees identify with ADHD (Attention-Deficit/Hyperactivity Disorder) or other mental health conditions before a formal diagnosis? This blog article provides practical advice on what action to take. 

The post-pandemic shift in workplace mental health

Mental health has moved from the margins of workplace discussion to the centre of people management. The COVID-19 pandemic intensified conversations about stress, anxiety, burnout and neurodivergence, while hybrid working gave many people more time to notice how they concentrate, organise work and manage social demands. One result has been a rise in employees exploring whether ADHD, autism or other neurodivergent conditions may explain long-standing difficulties at work.

This creates a sensitive question for UK employers: what should happen when an employee self-identifies as having ADHD, or another mental health or neurodevelopmental condition, before they have a formal diagnosis?

Why self-diagnosis has become more common

Self-diagnosis is not new. However, several factors appear to have made it more visible since the pandemic. Public awareness of adult ADHD has grown rapidly, helped by social media, lived-experience accounts and wider discussion of neurodiversity. At the same time, NHS assessment pathways have struggled to keep pace with demand. NHS Digital estimated in May 2025 that around 2.5 million people in England may have ADHD, including those without a diagnosis, and that up to 549,000 people may have been waiting for an ADHD assessment in March 2025. New referrals to mental health services for ADHD assessment rose by 13.5% between March 2024 and March 2025.

The King’s Fund has highlighted the lack of consistent national data and the scale of waiting times for adult ADHD assessment, noting that ADHD is suspected to affect around 3 to 4% of UK adults and that many adults remain undiagnosed. In 2025, it found substantial variation in how services collect and use data, with significant waits for assessment and concern that demand is continuing to rise.

The tension for employers

For employees, self-diagnosis can be an important first step towards understanding themselves and asking for support. For employers, however, it can raise difficult practical questions. A manager may be asked to adjust workload, deadlines, communication methods or performance expectations without medical evidence. Colleagues may perceive adjustments as unfair if the reasons are not visible or cannot be explained because of confidentiality. HR teams may worry about consistency, precedent and the risk of either over-medicalising ordinary workplace difficulties or dismissing genuine needs.

The tension is particularly sharp where performance issues already exist. An employee may feel that previously criticised behaviours e.g.

• Missed deadlines
• Disorganisation
• Emotional overload
• Difficulty sustaining attention

and these can be better understood through the lens of ADHD. An employer may accept that support is needed but still need to manage capability, conduct and business requirements. If handled poorly, both sides can feel mistrusted: the employee may feel disbelieved, while the employer may feel pressured to accept a diagnosis it is not qualified to confirm.

What reputable guidance says

The CIPD’s guidance on neuro-inclusion argues that organisations should build cultures where people feel comfortable talking about neurodiversity and where individual needs are considered proactively in people management. Its Neuro-inclusion at work guidance makes the case that neuro-inclusion should sit within both equality, diversity and inclusion and wellbeing strategies, rather than being treated as a niche issue.

ACAS guidance is especially important because it addresses diagnosis directly. It says a worker does not need a diagnosis to be considered disabled under the Equality Act 2010, and that employers should offer support whether or not someone has a diagnosis for their neurodivergence. ACAS also notes that long NHS waiting times and the cost of private assessment can mean workers have no proof to provide, even where support needs are genuine.

This does not mean employers must accept every requested adjustment automatically. It does mean that a diagnosis should not be treated as the only gateway to support. The better approach is to focus on the workplace barrier, the impact on the employee and the reasonableness of the proposed adjustment.

What the tribunals are saying

Employment Tribunal decisions are fact-specific and do not bind other tribunals, but recent cases show how these issues can play out. In Ms M Giltinane v Oxleas NHS Foundation Trust, the Tribunal held at a preliminary hearing that the claimant was disabled within the meaning of section 6 of the Equality Act 2010 by reason of ADHD throughout the relevant period of employment. The case underlines that ADHD can amount to a disability where it has a substantial and long-term adverse effect on day-to-day activities.

By contrast, Mr T Shevlin v John Wiley & Sons Ltd shows that an ADHD label will not automatically determine the outcome. Reports of the case indicate that the Tribunal accepted ADHD as a disability but dismissed the claims where the claimant had not disclosed the condition, the employer did not have actual or constructive knowledge of it, and the medical evidence did not establish that the performance issues complained about were caused by ADHD. The practical lesson is that employer knowledge and evidence of disadvantage matters.

More claimant-friendly outcomes can be seen where employers are on notice of ADHD and fail to act. In Ms B Khorram v Capgemini UK plc, reports state that the Tribunal upheld a failure to make reasonable adjustments claim after occupational health recommended measures including ADHD and neurodiversity awareness training, but the employer did not implement them before dismissing the employee during probation. The case is notable because training itself was treated as a potentially reasonable adjustment, not merely a general diversity initiative.

The Employment Appeal Tribunal also considered ADHD and autism in Stedman v Haven Leisure Ltd [2025] EAT 82. It overturned the Tribunal’s finding that the claimant was not disabled and sent the case back for reconsideration. Commentary on the judgment stresses that a diagnosis is not conclusive, but tribunals should not simply balance what a person can do against what they find difficult. The key question is whether the impairment has a substantial adverse effect on normal day-to-day activities, assessed properly and in context.

Court of Appeal authority on disability discrimination remains relevant in principle, especially on employer knowledge and reasonable adjustments. Employers should therefore avoid relying on the absence of a formal diagnosis as a complete answer where the facts suggest a worker may be experiencing a substantial, long-term impairment.

A practical way through

Employers should avoid making self-diagnosis a battleground. A more constructive question is: what is the employee finding difficult at work, and what reasonable, proportionate changes might help them perform effectively?

Good practice includes holding a supportive conversation, recording the practical difficulties described, considering temporary adjustments while an assessment is pending, and reviewing whether those adjustments work. Examples might include clearer written instructions, shorter check-ins, quieter workspaces, flexible start times, task prioritisation support, meeting adjustments or assistive technology. These adjustments are often low-cost and may benefit many employees, not only those with ADHD.

Managers also need training. Without it, self-diagnosis can be mishandled in either direction: dismissed as an excuse or accepted uncritically without a proper assessment of business impact. HR should help managers separate three issues that are often confused: the employee’s identity or suspected condition, the workplace barriers they face, and the standards required for the role.

So, has self-diagnosis created tensions?

Yes, in many workplaces it appears to have done so - but the tension is not caused simply by employees naming possible conditions. It is caused by rising awareness meeting slow access to formal diagnosis, inconsistent management practice and uncertainty about legal obligations. Post-pandemic demand for ADHD assessment, long waiting lists and greater openness about mental health have made this issue more visible and more urgent.

Employers should resist two extremes. One extreme is scepticism: requiring formal proof before offering any support. The other is abandoning standards altogether whenever a condition is mentioned. A fair workplace does neither. It listens carefully, explores reasonable adjustments, protects confidentiality, manages performance transparently and keeps the conversation focused on enabling people to do their best work.

Summary

Self-diagnosis may be imperfect, but it often reflects a real attempt by employees to understand barriers they have experienced for years. For employers, the challenge is not to become clinicians. It is to become better at designing work, managing people and responding to difference with fairness, evidence and humanity i.e. creating a modern workplace culture where people feel they can thrive.

Paul Beesley

Senior Consultant & Trainer, Beyond Theory 

31 July 2026

References:

CIPD, Neuro-inclusion at work, guide and report, 2024.

ACAS, Adjustments for neurodiversity: reasonable adjustments at work, 2025.

NHS Digital, ADHD Management Information – May 2025.

The King’s Fund, Adult ADHD assessments and diagnosis: data and service provision, 2025.

Ms M Giltinane v Oxleas NHS Foundation Trust, Employment Tribunal, 2023.

Mr T Shevlin v John Wiley & Sons Ltd, Employment Tribunal, 2024.

Ms B Khorram v Capgemini UK plc, Employment Tribunal, 2025.

Stedman v Haven Leisure Ltd [2025] Employment Appeal Tribunal 82.

Related blog articles:

Unlocking the potential of ADHD in the workplace: why business leaders should consider ADHD training

How to conduct an effective return to work interview

Dignity at work: why it matters more than ever in today’s workplace