It is believed he is in the Dublin area.
Mr Doran is 1.83m (6’) tall and thin. He has short brown hair, was unshaven and has blue eyes.
He was wearing a black tracksuit, a red three-quarter length jacket and a black peaked cap with ear covers.
He also had sunglasses on and was carrying a black rucksack and black bag.
Gardaí and Mr Doran’s family are concerned for his welfare.
They are asking anyone who has seen him or who can help to find Conor to contact the Garda Confidential Line 1800 666 111 or any Garda Station.