WASHINGTON — Rep. Patrick J. Kennedy will return to Congress Tuesday after an absence of about four weeks to undergo treatment for addiction, his office said Monday.

Kennedy spokeswoman Kerrie Bennett said the Rhode Island Democrat spent Independence Day weekend on Cape Cod with his father, Sen. Edward M. Kennedy, D-Mass., and other family members.

The senior Kennedy is suffering from brain cancer.

Kennedy announced through staff and friends on June 12 that he had entered a treatment facility earlier that week. He declined to be interviewed or to disclose any details about his treatment or his condition.

The action came not long after the third anniversary of Kennedy’s public acknowledgment — prompted by a highly publicized automobile accident on Capitol Hill — that he suffered from alcoholism and had been addicted to prescription pain medicine for most of his adult life.

He was treated after that 2006 incident at the Mayo Clinic in Minnesota — his second visit to the addiction center in less than a year.

Shortly before Congress adjourned for the Fourth of July recess, Kennedy appeared on the House floor at the request of Democratic leadership to cast a vote on a closely contested energy bill. Kennedy then returned to the Maryland treatment facility where he had undergone treatment, he told The Washington Post Monday.

Kennedy’s office issued the following statement from Kennedy late Monday afternoon:

“Tomorrow, I will be returning to Washington to get back to work on the bold legislative agenda set forth by the House leadership –– job creation, economic development, green energy, and health-care reform.

“The support and words of encouragement I have received over the past few weeks certainly help to support my efforts in recovery which I take seriously every day. I am feeling healthy and strong, and I am looking forward to continuing my work for the people of Rhode Island’s 1st Congressional District.”

jmulligan@belo-dc.com