Neil, 39, was last seen around 11.20pm on Sunday (May 30) in Don Place.
He is described as around 5ft 10ins, of slim build with short, dark hair. He was wearing red jeans, a grey jumper, black Adidas trainers and a black Adidas baseball cap.
Sergeant Craig Currie said: “We are growing increasingly concerned for Neil's welfare.”
Anyone with information can contact police on 101, quoting reference number 4553 of 30 May.