In Sullivan v Bury Street Capital Limited, the Employment Appeal Tribunal (EAT) considered the definition of disability under the Equality Act 2010, in relation to an employee suffering from paranoid delusions.  The employee argued that the delusions amounted to a ‘disability’ under the Equality Act 2010.


The Equality Act 2010 (the Act) protects people with disabilities (and other ‘protected characteristics’) from discrimination, harassment, and victimisation. Disabled employees are also entitled to ‘reasonable adjustments’ at work.

Under the Act, a person has a disability if

  1. they have a physical or mental impairment; and 
  2. the impairment has a substantial long-term adverse effect on the person’s ability to carry out normal day-to-day activities. 

While ‘physical or mental’ impairment is not defined, the Act states that ‘long-term’ constitutes an impairment lasting 

  • for at least 12 months; 
  • being likely to last 12 months; or 
  • the rest of a person’s life. 

Additionally, if an impairment ceases to have a substantial adverse effect on a person’s ability to carry out normal day-to-day activities, it is to be treated as continuing to have that effect if such effect is likely to recur.


Mr Sullivan was a sales executive at a small finance company, Bury Street Capital Limited (‘the employer’).  From approximately July 2013, following a split with his Ukrainian girlfriend, Mr Sullivan suffered paranoid delusions that he was “being continually monitored and followed by a gang or group of Russians” connected to his ex-partner.

The delusions affected Mr Sullivan’s timekeeping, attendance and record-keeping (which were already a matter of concern before 2013).  By July 2013, the CEO of the employer had recorded that Mr Sullivan’s belief about the Russian gang was having a significant effect on him. In August 2013, the CEO attributed Mr Sullivan’s poor attendance and erratic behaviour to his delusion and paranoia. But in September 2013, the Mr Sullivan appeared to improve and the CEO asked Mr Sullivan to join him on a business trip to New York. Mr Sullivan’s performance during the trip was commended and Mr Sullivan told the CEO that his condition was getting better. 

In February 2014, Mr Sullivan consulted a doctor about the “Russian gang problem”. His condition seemed to have improved in that he could still see the Russian gang, but he was able to cope with this and focus more on work. However, between July 2014 and September 2017, the CEO held regular reviews with Mr Sullivan, a constant theme of which was Mr Sullivan’s timekeeping and general attitude. Mr Sullivan did not mention that these problems were caused by his paranoid delusions. 

However, Mr Sullivan’s timekeeping and performance deteriorated again during 2017, and in September 2017, Mr Sullivan was dismissed. The reasons given for the dismissal included Mr Sullivan’s lack of timekeeping, communication, record-keeping and unauthorised absences.

Mr Sullivan lodged the following claims under the Act

  • discrimination arising from disability 
  • indirect disability discrimination; and 
  • failure to make reasonable adjustments. 

Mr Sullivan contended that throughout August 2013 to September 2017, he was a disabled person, as defined under the Act, due to his paranoid delusions. 

Employment tribunal decision

An employment tribunal reached the following conclusions.

  1. There was a substantial adverse effect on Mr Sullivan’s ability to carry out normal day-to-day activities, in line with the Equality Act definition of disability (see above). However, the substantial effect on Mr Sullivan’s ability to carry out normal day-to-day activities did not continue beyond September 2013. For example, the CEO would not have invited Mr Sullivan to New York if Mr Sullivan had not been able to perform effectively. This went against the argument that Mr Sullivan’s condition was ‘long term’.

  2. It was important for the tribunal to distinguish between Mr Sullivan’s continuing belief in the Russian gang, and the effect of the belief on his ability to carry out day-to-day activities. Mr Sullivan’s delusional beliefs existed throughout the relevant period, but the substantial adverse effect on his ability to carry out normal day-to-day activities did not persist for an equal length of time. 

  3. It was not likely that any substantial adverse effect, even if it was found, would continue for at least 12 months. 

  4. The episode of paranoid delusion that impacted his day-to-day life was not likely to recur.

Therefore, the tribunal concluded that Mr Sullivan was not disabled within the Act’s definition. It was unlikely that the substantial adverse effect would continue for 12 months or more. Accordingly, the Tribunal rejected Mr Sullivan’s claim of disability discrimination.

Employment Appeal Tribunal

Mr Sullivan appealed the tribunal’s decision. 

The EAT rejected Mr Sullivan’s appeal for the following reasons.

  • The tribunal lawfully concluded that the ‘long-term’ requirement in the definition of disability was not met.
  • The tribunal correctly distinguished between Mr Sullivan’s beliefs and the effect of Mr Sullivan’s beliefs on his ability to carry out normal day-to-day activities. 
  • Mr Sullivan’s condition was not likely to recur. The tribunal had approached the likelihood of the adverse effect recurrence correctly: the substantial adverse effect did in fact recur at a later date; but at the time the tribunal made its assessment, it correctly assessed that the condition was unlikely to recur. 


In Sullivan, the EAT’s narrow interpretation of the ‘long-term’ element of the disability definition in relation to recurring conditions is favourable to employers. It is not enough for an employee to show that they are suffering from a condition; they must show that its impact on their day-to-day life has been substantial and long term, and is likely to recur.  When considering whether a condition is ‘likely to recur’ an employment tribunal is entitled to assess the situation at the time; if a tribunal assesses a condition as unlikely to recur, it doesn’t matter if the condition did, in fact, recur at a later date.

So, the threshold for assessing recurring conditions is low, but employers can mitigate the risks of employees’ discrimination claims by maintaining regular communications with employees and keeping clear records on occasions when an employee’s performance is hindered by  a health condition – regardless of whether it falls within the meaning of a ‘disability’ under the Act.  That way, if an employee is protected under the Act, employers are more likely to be able to demonstrate objective, non-discriminatory, reasons for their actions. 

Finally, although the Mr Sullivan’s condition did not amount to a disability under the Act in these circumstances, the EAT did not rule out the possibility that a similar condition could be classed as a disability under the Act. Remember that serious long-term mental health conditions are protected under the Act, in the same way as all other health conditions.

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at October 2020. Specific advice should be sought for specific cases. For more information see our terms & conditions.

Date published

06 October 2020


View all