Much remains unknown about the mystery illness forcing Jesse Jackson Jr. into hiding, but last night's disclosure that the congressman is being treated for "mood disorder" at an inpatient care center gives mental health experts a better sense of what he's dealing with. Troublingly, it also raises more alarms regarding the severity of Jackson's illness. Here are the new issues the disclosure raises:

Why is Jackson receiving treatment remotely? Last night, Jackson's staff cited an unnamed physician saying the 47-year-old is "receiving intensive medical treatment at a residential treatment facility." That sort of inpatient treatment is rare for mood disorders, Ian Gotlib, professor of psychology at Stanford University, tells the Associated Press. "Depression is generally treated on an outpatient basis," he told the news agency. But "if doctors were concerned about the safety of the patient or if the disorder were severe enough, they could recommend inpatient treatment." In that case, treatment typically involves counseling and prescription drugs, which Gotlib said could take weeks. But more importantly, it raises questions of whether the "safety of the patient" was considered in Jackson's case. 

Gotlib's observation certainly wouldn't be the first time the issue of Jackson hurting himself was raised. On Tuesday, Chicago radio station WLS cited  "two high-ranking people on the Democratic side of the aisle, in both fundraising and in the legislative branch" saying Jackson's absence from Congress is due to a suicide attempt. Notably, Jackson's father, Jesse Jackson Sr., refuted the WLS report on Tuesday night.  “No, that’s not true,” he told Politico. Clearly, the longer details of Jackson's status remain unknown, the more speculation along these lines will continue.

What type of mood disorder does he have? This question remains a big unknown. According to Mental Health America, one of the country's largest mental health associations, there are four basic forms of mood disorders: "major depression, cyclothymia (a mild form of bipolar disorder), SAD (seasonal affective disorder) and mania (euphoric, hyperactive, over inflated ego, unrealistic optimism.)" Jackson's staff has not said which form of mood disorder Jackson suffers from but last night, NBC News' Phil Rogers quoted a family friend of the Jacksons attributing his problems to "severe clinical depression." The same source told NBC that Jackson was being treated for alcoholism but Rick Bryant, Jackson's spokesman, refuted the alcoholism claim while not disputing the claim about severe depression. Speaking with medical professionals, The Chicago Tribune's Deborah Shelton explains that severe depression is caused by the inability of the brain to properly regulate mood. "Common symptoms are extreme low levels of energy and motivation, as well as insomnia and altered eating habits," she writes.

Where is he? Jackson's staff has continued to keep his whereabouts a secret. It's possible that he's in Arizona—NBC's Andrea Mitchell reported yesterday that he was being treated there for alcoholism. The staff denied that substance abuse was a factor but they did not refute the other details in the report.

Why hasn't he been more forthcoming? An editorial in today's Chicago Tribune argues that Jackson's ailment is beyond a private matter at this point. "Jackson's prolonged and unexplained absence raises legitimate concerns about whether he can do the job he was elected to do. We don't see how his treatment could be compromised by providing some answers," the editors write. Others have been more sympathetic, however, such as The Daily Beast's Allison Samuels, who says mental illness "remains a taboo in the African-American community." She speaks with Dr. Gail Wyatt, a clinical psychologist at UCLA. “It is so sad that so many people of color feel they can’t come out and deal with their issues in a productive way,” Wyatt said. “They are forced to live a diminished life because our community won’t deal with this very real issue and so they don’t know how to get help." On the brighter side, Dr. Gotlib says there's a lot doctors can do to help patients with mood disorders. “The good news is that it’s clearly treatable,” he said.