During the 1920's Worcester State Hospital had a diploma (RN) nursing program. Saddly all of the records were destryoed in a fire some years ago. Also, during this time there were at least four hospital schools of nursing in Worcester which may have used Worcester State Hospital for psychiatric nursing experience. All of these programs and some of the hosiptals are now closed: Worcester City Hospital, St. Vincent Hospital, Hahnemann Hospital, and Memorial Hospital. Other smaller community hospital in Central Massachusetts had nursing programs at this time as well and they too most likely had students at Worcester State Hospital.
You can try contacting the hopitals to see if there is a contact person for the alumni association for the now closed schools of nursing.
Also, the Worcester Historical Society Library may have some information on these schools. Good luck with your searching.