Employers and employees should be aware that the American Disabilities Act covers psychiatric disabilities as well as physical disabilities.  Therefore there should be no discrimination in the workplace against anyone with a psychiatric disability.  Employers should make accommodations to help those with psychiatric disabilities to perform their jobs.
Human Resource Executive Online advises:
The National Institute of Mental Health in Bethesda, Md., estimates that one in five people will experience a psychiatric disability in their lifetime, and one in four Americans currently knows someone who has a psychiatric disability. In addition, most employers have at least one employee with a psychiatric disability.
Melissa Fleischer, president and founder of HR Learning Center in Rye, N.Y., says HR managers should understand their legal obligations regarding such employees under the Americans with Disabilities Act, as well as their state fair-employment laws, which includes providing reasonable accommodations for an employee’s particular psychiatric disability.
Such accommodations can include an extended leave of absence — even above the 12-week leave of absence provided under the Family and Medical Leave Act, modifications to the employee’s work schedule or modifications to the employer’s work policies, Fleischer says. For example, workers may need to work separately from others and away from customers, or have access to water fountains or water bottles when it’s time to take their medication.
If  job applicants or employees have the qualifications to do a job, they cannot be eliminated from the hiring or promotion pool of applicants just because they may need certain accommodations to do the job well.  If a psychiatric disability is interfering with an employee’s ability to do his or her job. the employer’s first response should be to discuss this with the person and make referrals for the employee to get the support, counseling, or medical treatment needed to get back on track with the job.  If the employee refuses to get the recommended help, and accommodations are still not helping him or her to do the job in a satisfactory manner, it may be a reason for dismissal.  But only after these steps have been tried.
Be aware that state laws may come into play in this type of situation as well.  HR departments must keep up with all the legal requirements of the ADA and their local labor laws.