Could an employee with an illness that comes and goes, such as depression, be covered by the Equality Act 2010?

Yes, an employee with an intermittent illness such as depression could be covered by the Equality Act 2010. A disability under the Equality Act 2010 is a physical or mental impairment that affects a person's ability to carry out normal day-to-day activities. The adverse effect must also be substantial and long term. An impairment will be treated as continuing to have a substantial adverse effect on a person's normal day-to-day activities if it once had that effect and the effect is likely to recur (para.2(2) of sch.1 to the Act).

Depending on medical evidence, this "likely to recur" provision can cover employees with mental illnesses such as depression, where the effects of the condition may come and go over time.