These types of cases are very fact-specific. On one hand, an employer is not supposed to discriminate on the basis of mental health infirmity, but on the other, an employer cannot also endanger the well-being of its staff. I would speak to an attorney privately about this.
The answer provided is for general information purposes and cannot be relied upon. In order to provide legal advice, one must engage with a live attorney; this answer does not create such attorney-client relationship.
You should consult an attorney who specializes in employment law. If you are a federal government employee, you should consult with a federal sector employment lawyer as there are different laws for different types of employment.
This response does not constitute legal advice. It is intended for educational purposes only.