In order for an employee to satisfy the definition of disability, they must have a physical or mental impairment, which has a substantive adverse impact, on their normal day to day duties, which has a long term effect.
The Claimant suffered from depression caused by work related stress. However, at the time of his dismissal, this had not lasted for twelve months, and so the tribunal held that he was not disabled as his impairment was not long term.
The EAT held that the tribunal had been wrong. What should have been considered was whether the depression was likely to last twelve months, or whether it could well happen in the future (meaning more probable than not). As the tribunal did not take this into account, the case was remitted.
Parnaby v Leicester City Council.