I want to know if my great uncle Arthur McManus was a patient in St. Elizabeth Hospital, Wash.DC after WWI

I am searching for the records of my grandfathers brother. My relatives would mention that my grandfather had a brother who was hospitalized in a mental institution due to trauma from serving in World War One, and who was buried in Arlington National Cemetery, but I have no record of that. Iam writing to find any records that he was a patient in St. Elizabeth Hospital in DC.

His birth is registered in the District of Drumshambo, Union of Carrick-on-Shannon, County of Leitrim, Ireland (which was part of the United Kingdom at the time)

Name: Arthur McManus

Born: January 10, 1889

Birthplace: Driney, Leitrum, Ireland

Parents: Matthew McManus, Anne Early McManus

Arthur emigrated to the United States with his brother Owen, my grandfather, on the SS St.Paul, from Liverpool to New York City in October 1915.

He went to New Haven, Connecticut to live with his sister Katie.

There is a military census record of Arthur recorded on Feb 19, 1917 in the State of Connecticut. His address is listed as 44 Spring St., New Haven, Conn.

Any information about Arthur would be most appreciated.

I look forward to your response. Thank you.

Best Regards,

Mary Ellen Muldoon