I have had two employers since my Bipolar diagnosis, and I told both of them. The first position was at a pharmacy and the boss there was just so lovely and sweet about it all; I'd told him during the interview and still got the job, despite my lack of formal qualifications. He did know my granddad though and was therefore very sympathetic when I burst out crying at work during my first birthday without him.

At the first job, when I required days off due to mental health, I just went ahead and told him. He even decided to give me PAID leave for a number of weeks. Eventually I left the role, due to my unstable state but also because I did feel guilty taking so much time off when he needed me there working. I regret that decision immensely - it was a good job. However, I suppose my health comes first but I digress.

Now. At my second job, I didn't tell them during my interview and didn't admit it until after a month or so in the role - I was struggling and decided to come out with it. Unfortunately, they weren't as understanding. Don't get me wrong; my assistant manager was very understanding and sympathetic, the only issue is that they didn't make reasonable adjustments for my disability which is actually a legal requirement under the UK Equality Act 2010.

I've since learned that absolutely nothing stays confidential in that place and the upper management are extremely judgemental. They have a few levels of management in the store, the hierarchy was as follows: Sales Assistant, Sales Co-Ordinator/Supervisor, Assistant Manager, Manager. Now, the Assistant Manager has been fairly understanding. It's the manager and the Co-ordinators that have not treated me well or fairly since confessing my illness.

Due to those facts, when I can't handle the day, I just call in sick for any reason - sick bug, diarrhoea, whatever. Even saying I have diarrhoea is less embarrassing and awkward for me!

So to summarise, you don't have to disclose your illness. You are not obliged to in any way, and the law protects your right to keep your condition private. Therefore I advise using other reasons.