CHICAGO (AP) — U.S. Rep. Jesse Jackson Jr. is under intensive medical treatment for a "mood disorder," his office announced in a brief statement Wednesday, more than a month after the Chicago Democrat quietly went on medical leave of absence.

The statement gave no details about where Jackson was being treated. Staff members said the statement was from Jackson's physician but that the doctor's name and location would not be released because of federal privacy laws.

"The Congressman is receiving intensive medical treatment at a residential treatment facility for a mood disorder," the statement said. "He is responding positively to treatment and is expected to make a full recovery."