here are the criteria for mandatory accommodations under the ADA:

1) the employer must have at least 25 employees to be included in the Act
2) the employee must be able to perform the Substantial Duties of the job with accommodations
3) the request for accommodations must not put an unreasonable financial burden on the employer

that being said, you do not have to reveal the exact diagnosis of your disability, but you may be requested to state the nature of the impairments: ie. 'stress related sleep distubances due to disrupted sleep schedule'

the exact wording of the request is important. here is an approved example:

I am requesting an Accommodation for a Disability Related Functional Impairment under the provisions of the 1990 Federal Americans with Disabilities Act.* (mandatory)

Specifically, due to increased stress from sleep deprivation caused by changes in scheduling, i am requesting that i be exempted from working between the hours of ( 8 p.m. to 8 a.m. ??).

Please respond to this request in writing within 30 days of its submission.

i hope this works for you.
best wishes~
Gus