[Kate*]

Documented mental health issues are covered under the ADA. If they know about it, and you can only work 25 hours or less, document in writing that you've discussed it with them, which should be enough. You might want a doctor or therapist's note just in case, and then if they try to give you a hard time, or force it on you, you're protected by law. Obviously, you would bring this up as a last resort if they make things difficult. Start with civil conversations, and if needed work up the chain of command. Be firm, but professional.