PPD and Medical Leave Of Absence.

Marjorie • "Just staying on it I guess, long as she can."
Hello everyone. I'm wondering if anybody knows about PPD as a medical reason for a medical leave of absence from work. Typically the paperwork requires the signature and diagnosis from an MD. I'm trying to find someone through my insurance to help me with treatment but there don't seem to be many (if at all) psychiatrists that specialize in PPD that take insurance. Does a psychologist or therapist have the authority to dismiss you from work or give you a prescription if necessary? I work in the travel industry. 
My job requires me to be gone from home 4 to 6 days at a time. I'm having severe anxiety attacks and other mental health issues as the return to work date approaches. 
Any information anybody might have could help and is greatly appreciated. Thank you!