If they have any sense at all they will try and find out what was the root cause of your problems (if they don't know already - I don't know how much you have talked to your manager) and do everything feasible to alleviate it. I'm in the NHS; short staffing is a way of life so we work hard to keep people in work, because we know how difficult it will be to replace them - both the person, and the expertise that they have. Everyone who's been off sick, with mental health problems or otherwise, has an interview with their manager and, if necessary, occupational health, to decide what hours and work would be best for them. Sometimes people can go back to the same job if they phase into it gradually, other times we have to change what they're doing to enable them to carry on working. We can't sack people purely on the grounds that they can't do the job they used to be able to do. I'm not sure if this is just an NHS thing, or whether it applies to other areas as well - I hope so.