Assuming US law: If you work for a company "professional" enough to start a performance improvement plan instead of just firing you, then they are likely to mov

Assuming US law: If you work for a company "professional" enough to start a performance improvement plan instead of just firing you, then they are likely to move slowly and carefully in anything that they know involves a disability. This includes mental and psychiatric disabilities. (I'm using the word "disability" here because that's the word the law uses.) That employment law is very complicated, and a wrong move could create big liability for them. I'd strongly suggest that you disclose to them that you are seeking treatment regarding a mental health issue, and maybe say it's major depression and/or ADD. I probably wouldn't disclose more without talking to a lawyer (or at least, a forum with more people trained in employment law than here). I would state that I believed I could do the job--you say your work has been commended--but may require some accommodation. You can search the phrase "reasonable accommodation", and see examples of how other people have resolved similar situations. If you do this, then you'll probably buy yourself at least a couple months. As other commenters note, you may be eligible for paid leave. Even better, you may be able to negotiate a modified job description that works both for you and for your employer long-term. You may also be able to use this time to switch to a different role, inside or outside your present employer. There's some risk in disclosing that you're dealing with a mental health issue, since there's a stigma associated with it. The company is supposed to keep your information private, but sometimes they don't. There's probably worse stigma associated with just being generically unreliable, though. So I think it's in your interest to disclose. Please don't feel reluctant to use all the tools that employment law creates to help you in this circumstance. (Of course, also remember that the company is complying because they have to, not necessarily because they're as warm and fuzzy as the HR brochures might suggest.) I hope you find yourself in a better situation very soon, and I think that you will.