Kennedy, a Rhode Island Democrat, plans to seek treatment at the Mayo Clinic in Rochester, Minnesota.

He announced his decision on Friday night, then planned to travel to Minnesota later.

Kennedy, who has struggled with addiction and depression, said he had checked into the Mayo Clinic over the Christmas holidays and returned to congress "reinvigorated and healthy".

"Of course, in every recovery, each day has its ups and downs, but I have been strong, focused and productive since my return, " Kennedy said in a statement obtained by the Associated Press.

The congressman said he became concerned about his condition after Thursday morning's car accident.

"I simply do not remember getting out of bed, being pulled over by the police, or being cited for three driving infractions, " he said. "That's not how I want to live my life.

And that's not how I want to represent the people of Rhode Island."

The congressman's father, Senator Edward Kennedy, a Massachusetts Democrat, issued a supportive statement in which he said he was proud of his son for admitting his problem and taking steps to correct it.

"He has taken full responsibility for events that occurred. . . and he will continue to cooperate fully with any investigation, " the elder Kennedy said.