Police and the family of Abhristin Ocadhlaigh are becoming increasingly concerned for his welfare.
The 49-year-old was last seen almost one week ago.
He left the Royal Victoria Hospital in Belfast at around 6.45pm on Sunday 2 May.
Abhristin is described as slim to medium build, 5ft 6” in height, with black short hair.
He is believed to have been wearing a burgundy jumper with small white dashes, navy/dark jeans and navy moccasin-style slippers.
There are reports that he may have subsequently been seen in the Portadown area.
Officers are appealing to Abhristin, or anyone with information on his whereabouts, to contact them on 101 quoting reference 1639 of 2/5/21.