U.S. Rep. Jesse Jackson Jr., a Chicago Democrat who took a hushed medical leave two months ago, is being treated for bipolar disorder, the Mayo Clinic announced Monday.
The Rochester, Minn.-based clinic specified his condition as Bipolar II, which is defined as periodic episodes of depression and hypomania, a less serious form of mania.
"Congressman Jackson is responding well to the treatment and regaining his strength," the clinic said in a statement.
Bipolar II is a treatable condition that affects parts of the brain controlling emotion, thought and drive and is likely caused "by a complex set of genetic and environmental factors," the clinic said. The statement also mentioned that Jackson underwent weight loss surgery in 2004 and said such a surgery can change how the body absorbs foods and medications, among other things.
The statement Monday was the most detailed to date about the congressman's mysterious medical leave, which began June 10. But it raised new questions about when the congressman can return to work.
A Jackson aide said last week that the congressman was expected back in the district within a matter of weeks, but Jackson's spokesmen declined to comment Monday.
His father, the Rev. Jesse Jackson, wouldn't say much about the diagnosis.
"I'm glad he's getting the treatment he needs and is responding well," the elder Jackson said, adding that "there's no timetable" for his recovery.
Experts and mental health advocates say many people are able to work and function in their daily lives while managing treatment.
Treatment for bipolar disorder includes medication and psychotherapy, according to the National Institute of Mental Health. The institute estimates about 5.7 million American adults suffer from the disorder, which can be a lifelong disease.
At least one other member of Congress has suffered from it while in office.
Former Rhode Island Congressman Patrick Kennedy has talked openly about his struggles with bipolar disorder and addiction. He's become an advocate for removing stigma linked with mental illness.
The son of the late Massachusetts Sen. Edward Kennedy was a congressman for 16 years and retired last year.
Kennedy was treated at the Mayo Clinic himself for addiction and depression in 2006 after a late-night car crash at the U.S. Capitol. Kennedy said he and Jackson have a lot in common. Both have famous fathers, and they served with each other on the House Appropriations Committee.
He said he will speak with Jackson on Thursday about his own time in recovery and said he can relate what it's like to struggle and be in public life.
Jackson's office initially described his medical condition as exhaustion and announced it nearly two weeks after he went on leave. Later his office disclosed that he had "grappled with certain physical and emotional ailments privately for a long period of time." A statement from an unnamed doctor called it a "mood disorder."
Earlier this month, Jackson's office announced that he was at Mayo and being treated for depression and gastrointestinal issues, after a transfer from the Sierra Tucson Treatment Center in Arizona.
The Mayo Clinic's statement Monday stopped short of directly tying Jackson's weight loss surgery with his mental health problems. Mayo Clinic spokeswoman Traci Klein declined to comment.
Jackson underwent a duodenal switch procedure in 2004, which involves removing part of the stomach and rearranging the intestine so less food is absorbed. He lost 50 pounds.
Experts don't consider depression or bipolar disorder to be a side effect of weight loss surgery, said Dr. Vivek Prachand, associate professor of surgery at University of Chicago. Most reputable surgery centers screen patients for mental health problems before weight loss surgery, he said. People already taking medications for depression can undergo weight loss surgery but may need their medications adjusted afterward.
Prachand added that surgery is a drastic change that can trigger an episode in someone with a history of depression.
Jackson aide Rick Bryant said last week that Jackson appeared in good spirits and wanted him to push forward on projects in the district, which includes Chicago neighborhoods and South suburbs. Jackson, who first won office in 1995, is on the November ballot with two little-known candidates and is widely expected to win re-election.
The timing and manner in which the medical leave was handled has invited scrutiny.
Jackson is under a House Ethics Committee investigation for ties to imprisoned former Gov. Rod Blagojevich. Jackson's office announced his leave just days after a former fundraiser connected to the probe was arrested on federal medical fraud charges.
Jackson has denied wrongdoing.