Graham Roskell was reported missing on Saturday 3 November 2012 when he left Harrogate District Hospital where he was receiving treatment.
He was last seen on CCTV footage leaving the hospital at around 8am.
Police have been searching for him in and around the Harrogate area since he disappeared.
Every police force in the country has been made aware of Mr Roskell’s disappearance in case he has travelled further afield, and his profile is featuring on the Missing People website www.missingpeople.org.uk
Mr Roskell’s family and friends have also been searching for him and have set up a website and Facebook page to raise public awareness, generating outstanding public support.
Hundreds of people have been volunteering their time to help with the search and distribute posters and leaflets.
“Our dad has been missing and not receiving treatment for his condition for over a week now. Every day that passes feels like a year, and we are truly grateful for the help we have had from everyone to help us get this far.
Our family has been torn apart and every member of our family has been out there searching. The searches by the public and the police are also still on going and we would like to thank those people for not giving up hope."
“Although farmers, landowners and rural businesses may have already checked their outbuildings and sheltered areas, we are urging those people to regularly check, as he may have moved around, or be unable to respond to people simply calling his name.
There are now over 5000 members on the “Find Graham Roskell” Facebook page, and more are joining every day. It’s not too late to get involved and help in any way you can as we still know that he is out there somewhere.”
More top news
A couple in North Tyneside have seen off an intruder believed to be armed with a machete.
Brighter skies follow morning rain for both Saturday and Sunday. Winds stay strong. Mild Saturday, cooler on Sunday
Hartlepool United's great escape bid continues in League Two this afternoon - they welcome Cambridge to Victoria Park.