The law says that to claim disability discrimination, a worker has to show that the disability had a substantial and long-term adverse effect on their ability to carry out normal day-to-day activities. In Sullivan v Bury Street Capital Ltd, the Employment Appeal Tribunal (EAT) held that an employee with paranoid delusions was not disabled as the effect on his ability to carry out normal day-to-day activities was not long term. 

Basic facts

Mr Sullivan, a senior sales executive, had a tense relationship with the chief executive (Mr Drake), because of his relaxed attitude in relation to adhering to office hours and his failure to document his activities adequately.

In March 2013, he started a relationship with a Ukrainian woman which lasted for approximately two months. After they split up, he became convinced that he was being followed and monitored by a gang of Russians. As a result he had difficulty in sleeping which affected his attendance and behaviour at work from about May 2013.

Mr Drake was aware of what he called this “extreme paranoia”. However, during a work trip to New York in September 2013, Mr Drake noted that he was performing well at business meetings and Mr Sullivan himself said his condition had improved.

In February 2014 and May 2014, Mr Sullivan consulted a doctor and a psychologist who noted that his condition had improved. For example, he was engaging with friends and was managing to concentrate on work.

Between July 2014 and September 2017, Mr Drake conducted regular reviews with Mr Sullivan in relation to his timekeeping and attitude at work. A new colleague who had joined the company in September 2014 and sat near to him, did not notice any change in behaviour between then and September 2017.

However, due to concerns about his behaviour and timekeeping, Mr Drake met with Mr Sullivan on 5 September 2017 to discuss how his remuneration would be structured. Mr Sullivan was subsequently signed off sick and on 8 September 2017 was given notice of his dismissal. Mr Sullivan lodged a number of claims, including disability discrimination.

Tribunal decision

In relation to his claim for disability discrimination the tribunal concluded that from around May to September 2013, Mr Sullivan suffered a substantial adverse effect on his ability to carry out normal day-to-day activities. However, as the paranoia was not long-term (it only lasted a few months) and was not likely to recur, his disability discrimination claim could not succeed.

The tribunal acknowledged that he suffered a recurrence of his delusional beliefs from approximately April 2017 and that they had a substantial adverse effect on his ability to carry out normal day-to-day activities. However it was not likely that they would last for 12 months. In coming to this finding the tribunal took into account that the previous episode in 2013 had lasted three to four months.

In any event, the tribunal held that the company did not have knowledge of his disability nor could they have reasonably been expected to know about it at the relevant time based on the observations of Mr Drake and his colleagues.

EAT decision

Dismissing the appeal, the EAT held that, although the delusional beliefs persisted, the tribunal was right to distinguish between those beliefs and the effect that they had on Mr Sullivan’s ability to carry out normal day-to-day activities. Although the medical evidence stated that there was a substantial adverse effect on his ability to carry out normal day to day activities between August 2013 and September 2017, the EAT held that the tribunal was entitled to take into account the contradictory evidence of Mr Drake and the work colleague.

The tribunal was also entitled to take into account that, as his poor timekeeping and poor documentation (being the substantial adverse effects) existed prior to his delusional beliefs, they did not have a substantial adverse effect throughout the relevant period.

With regard to the recurrence of the substantial adverse effect, the tribunal had to make its decision on the basis of the circumstances “prevailing at the time”. However, that did not mean that when the effect did in fact recur, the tribunal was bound to find that it was likely to recur. Nor did it prevent the tribunal from finding that when it did recur in 2017, a further recurrence was likely, taking into account that what had triggered his disability at that time, namely the discussion about remuneration, was a one-off event.

Finally, in terms of the company’s knowledge of his condition, the EAT held that the tribunal was entitled to rely on a colleague’s evidence which was relevant in this case. The fact that there were references to paranoia between September 2013 until April 2017 did no more than demonstrate he had an impairment. However, that did not establish that the employer could reasonably be expected to know that it had a substantial and long-term adverse effect on his ability to carry out normal day-to-day activities.


The finding that the claimant in this case did not have a recurring disability is unusual and particular to its facts. In most cases where there is evidence of an impairment and that there was a recurrence of a substantial adverse effect, it would be usual for a tribunal to find that the person did have a disability.