David Smith has been missing since Wednesday, July 1, at 12.05pm and does not have his medication.
Police said they were concerned about the Epsom man who is known to use other names, particularly the surname Morter.
They said he had links to various areas of London including Ealing, Camden, Westminster, Brixton, Hackney and Kilburn.
They say he is about 6ft 1 inches tall, of medium build, with short brown hair and blue eyes.
He was last seen wearing a red t-shirt with black writing on it and black jogging bottoms.
He went missing in June 2013 when police issued an appeal for him but he was found later.
Call Surrey Police on 101 if you know where he is or online at https://my.surrey.police.uk/splonlinereportingweb#sthash.7iBZirCt.dpuf
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