The EAT said that tribunals did not have to find a specific medical condition that an employee was provably suffering from as a prerequisite for ruling that they had been discriminated against.
Tribunals should examine an employee's condition and the effect it had on their work and proceed from there, Mr Justice Underhill ruled.
"There are … sometimes cases where identifying the nature of the impairment from which a claimant may be suffering involves difficult medical questions; and we agree that in many or most such cases it will be easier – and is entirely legitimate – for the tribunal to park that issue and to ask first whether the claimant’s ability to carry out normal day-to-day activities has been adversely affected – one might indeed say 'impaired' – on a long-term basis," he said in the ruling.
The EAT said that if someone behaves as if they are suffering depression and their abilities suffer as a result, then tribunals will most likely find that they are suffering from depression and can be protected under the Disability Discrimination Act (DDA).
"If it finds that it has been, it will in many or most cases follow as a matter of common-sense inference that the claimant is suffering from a condition which has produced that adverse effect - in other words, an 'impairment'," he said. "If that inference can be drawn, it will be unnecessary for the tribunal to try to resolve difficult medical issues of the kind to which we have referred."
The case involved a woman who had suffered from depression and who applied for a job at law firm DLA Piper. When the woman, identified only as J, told the company about her history of depression it withdrew its job offer, claiming that it had stopped hiring because of the recession.
J claimed that the job offer was withdrawn because of her disclosure of her depression and said that this was a breach of the DDA.
An Employment Tribunal rejected J's claim, saying that J was not suffering from 'clinical depression' at the time of the job offer and its withdrawal.
The EAT ruled that the Employment Tribunal was wrong and must re-consider the issue of whether J was depressed at that time.
J had received a negative assessment at work in the run up to her application for the job with DLA Piper and this had triggered feelings of anxiety and despondency. The Tribunal said that this was directly related to the appraisal and was not 'clinical depression' but a simple response to events in J's life.
The EAT reconsidered that issue and found that the Tribunal should have found that J had suffered depression in 2005 and 2006 and sought to establish whether that was likely to recur. If it was, it should have found that she was suffering from depression - and entitled to DDA protection – when the job offer was made and withdrawn.
The EAT said that it was often desirable to distinguish between depression and anxiety created by events, but not always helpful.
"The first state of affairs is a mental illness – or, if you prefer, a mental condition – which is conveniently referred to as 'clinical depression' and is unquestionably an impairment within the meaning of the Act," the EAT ruled. "The second is not characterised as a mental condition at all but simply as a reaction to adverse circumstances (such as problems at work) or – if the jargon may be forgiven – 'adverse life events'."
"If, as we recommend … a tribunal starts by considering the adverse effect issue and finds that the claimant’s ability to carry out normal day-to-day activities has been substantially impaired by symptoms characteristic of depression for twelve months or more, it would in most cases be likely to conclude that he or she was indeed suffering 'clinical depression' rather than simply a reaction to adverse circumstances: it is a common-sense observation that such reactions are not normally long-lived," it said.
Employment law expert Morag Hutchison said that the case was similar to many workplace disputes, and that the ruling could make it easier for employees to claim the protection of the DDA.
"It is a common experience for employers to be faced with an employee taking time off work in response to an event such as a negative appraisal, a disciplinary investigation or not getting a role they applied for," she said.
"The EAT held that tribunals should be more concerned with the impact of the employee's symptoms on day-to-day activities when deciding if an employee was disabled or not rather than a technical medical assessment, arguably making it easier for employees to satisfy the definition of disability," said Hutchison.
The case was sent back to be re-considered by a different tribunal.