I recently got involved in a discussion over whether or not prospective employees should disclose hidden disabilities to the prospective employer. There's no simple answer to this very complicated issue.
On the one hand, it is natural to want to keep private what is private. Persons with disabilities are not required to disclose their disabilities and are often concerned about losing their job or job opportunity if they do disclose. And, truthfully, that perceived risk is more real than you may think. Discrimination does exist. I could cite more examples than you can imagine.
On the other hand, when a disability becomes an issue during employment or the employee expresses the need for a job accommodation at any time, the employer perceives deception and that fuels discrimination either for that employee or later ones. Certainly, if the disclosure and request for accommodation only come when an employee is at risk of disciplinary action, the employer will feel played. And that perception could be real.
There is no perfect solution.
When I’m working with persons with disabilities, I recommend that they focus on their talents, skills and abilities. Sell the employer on what a good employee he will be. Once an offer, either conditional or firm, is made, disclose the disability, using a matter-of-fact approach like, “I have (disability). It affects me (like this) and this (accommodation) is what I do to manage/accommodate it so that I can still be the best employee you ever had.” Straightforward. Simple.
There will still be employers who will find an excuse to not hire this person, but that employer would discriminate at some point in time anyway.
Employers need to focus on hiring a person that can get the job done. Focus on the essential functions of the job and the skills required to do them. Look for the candidate that can do that for you. A job accommodation is simply another tool in the toolbox for the employee. There will always be some employee who is not honest with the employer, but that employee is not necessarily someone with a disability.
Employers, employees and job candidates all need to focus on the real goal which is getting the job done.