Rep. Jesse Jackson Jr.’s mystery mood disorder has now been officially diagnosed as bipolar disorder, the Chicago Sun-Times reports. The Illinois congressman took a medical leave of absence from office June 10 and two weeks later issued a statement saying the leave was due to exhaustion. On Monday the Mayo Clinic in Minnesota released a statement saying the congressman is in treatment for bipolar II depression and is responding well. Jackson underwent gastric bypass surgery in 2004. He plans to run for reelection in the fall.