Can we performance-manage someone with ADHD?

Yes — but only after reasonable adjustments are in place and you've separated genuine underperformance from difficulty arising from the ADHD. Where ADHD is a disability, that duty applies from day one, diagnosis or not. Performance management is lawful; it just has to be done in the right order, or a process that looks fair on paper can still be discrimination.

First: adjust the job, then separate cause from conduct

Before any capability meeting, ask the employee what they need and make and document reasonable adjustments to how they work. Acas says employers should do all they reasonably can to support a disabled person before taking formal action, and it advises offering support whether or not the person has a formal diagnosis — a worker does not have to prove a diagnosis to be covered. Then look hard at the shortfall and ask which part is a real performance issue and which part is the ADHD showing through tasks you have not yet adjusted. Lateness, missed deadlines and disorganisation that flow from the impairment are not the same as a refusal to do the job, and they call for different responses.

Then: run a full, fair capability process — and adjust the process too

Once adjustments are in place, you can run a normal capability or performance procedure: clear standards, honest feedback, a reasonable period to improve, support, and notes throughout. The point most employers miss is that the duty to make reasonable adjustments applies to the procedure itself, not only to the job. So the capability process may need adjusting too — written points ahead of meetings, extra time, a longer improvement window, a support person, or breaking targets into smaller steps. Commission an occupational-health assessment to evidence what the employee can manage and what helps, and keep records of every adjustment offered and every conversation. That evidence trail is what makes the process defensible.

The risk flag: dismissing for ADHD-related performance

Treating a disabled employee unfavourably because of something that arises from their disability — including ADHD-driven underperformance — is discrimination arising from disability (section 15 of the Equality Act 2010) unless you can show it is a proportionate way of meeting a legitimate aim. In practice you can only realistically justify dismissal once adjustments have genuinely been tried and exhausted, no suitable alternative role exists, and the decision is proportionate. Acas is clear: get legal advice before any dismissal. Remember too that disability protection has no qualifying period — it applies from day one of employment, so probation is no shield, and it can bite even without a formal diagnosis.

This page is general information, not clinical or legal advice.