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I'm sorry to hear about your situation. Yes, the ADA does protect an individual in such a situation, although there are certain obligations on the employee. That is, an employer with 15 or more employees has to "reasonably accommodate" a disability. The ADA does not contain a list of medical conditions that constitute disabilities. Instead, the ADA has a general definition of disability that each person must meet on a case by case basis (EEOC Regulations . . . , 2011). A person has a disability if he/she has a physical or mental impairment that substantially limits one or more major life activities, a record of such an impairment, or is regarded as having an impairment (EEOC Regulations . . . , 2011).
However, according to the Equal Employment Opportunity Commission (EEOC), the individualized assessment of virtually all people with bipolar disorder will result in a determination of disability under the ADA; given its inherent nature, bipolar disorder will almost always be found to substantially limit the major life activity of brain function (EEOC Regulations . . . , 2011).
Now an employer has to actually know about the disability (or have a reasonable basis to believe that the person has said disability) before the obligation to "reasonably accommodate" said disability kicks in. Then the question becomes whether or not the employer could accommodate the disability and whether or not the employer tried to.
So the employee has to inform the employer of the disability AND what accommodations the employee is requesting. Ultimately the ADA is "backward looking", in that the question usually is after a breach of the ADA. It comes up when the employer doesn't do something that it should have, and the question is whether or not it should have under the circumstances. But assuming that the employer knows about this AND that the accommodation requested is reasonable in light of the circumstances, the failure to do what is requested would be an ADA violation.
Hope that clears things up a bit. If you have any other questions, please let me know. If not, and you have not yet, please rate my answer AND press the "submit" button, if applicable. Please note that I don't get any credit for the time and effort that I spent on this answer unless and until you rate it positively (good or better). Thank you, ***** ***** luck to you!