Max Aitken, from the Stirling area, was reported missing after he left Forth Valley Royal Hospital, Larbert, around 5pm on Monday, May 15.
He was seen later that day via CCTV in West Port Street, Edinburgh, around 7.35pm. He was last captured heading in the direction of the Grassmarket.
There has been no information on Max’s whereabouts since and police are growing increasingly concerned for his welfare.
Max is described as a white man, around 5ft 6” with a muscular build. He was last seen wearing a beige jacket, a pink polo shirt and navy tracksuit bottoms with light stripes down the side.
He was also wearing grey sandshoes/ trainers.
Anyone with information about where Max may be is asked to contact officers at Stirling Police Station on 101, quoting incident number 0726 of May 16.