Police are appealing for the public's help in trying to find Aaron Fiveash, who has been missing from his Bournemouth home since Monday.
The 36-year-old was believed to have left his parents' home in Sunnylands Avenue at around 5:30am on 6th January.
The National Police Air Service helicopter is continuing to search coastal and river areas.
Aaron's father, Dennis Fiveash said, "Please help us find our son. He left our house in the early hours of Monday morning in a confused state.
"He needs your help. We need your help to find him."
Anyone with information or knowledge as to Aaron's whereabouts should call Dorset Police on 101, quoting incident number 6:61.