Neil was last seen leaving the Red Bear pub in Thirsk Market Place at 6.13pm on Wednesday (April 27) and is pictured on CCTV wearing a short sleeved burgundy t-shirt, black body warmer, grey chinos and grey or black trainers with a white sole.
Neil, of Swale View, Topcliffe, is around 1.7m tall with hair that is starting to go grey and walks with a limp. He has no upper teeth and is non-verbal.
Officers are extremely concerned for his welfare.
Neil often uses the bus to travel around and was meant to be getting the Ripon bus home to Topcliffe on Wednesday evening but did not return home.
If you have any information which could help to locate Neil please ring 101 or 999 with an immediate sighting, and reference 12220071948.