Sen. John Fetterman will likely be in hospital for a few weeks for clinical depression treatment

Sen. John Fetterman, D-Pa., will receive inpatient hospital care for a few weeks as he seeks treatment for clinical depression, a senior staffer for the senator told CNBC on Friday.

The expected length of Fetterman's hospital stay was shared hours after his office revealed that the 53-year-old freshman lawmaker checked himself into Walter Reed National Military Medical Center in Bethesda, Maryland, on Wednesday night.

Fetterman suffered a life-threatening stroke on the campaign trail last year, and he has continued to experience health issues in office. He was hospitalized last week after feeling lightheaded, though doctors ruled out the possibility that he suffered a second stroke, his office said at the time.

"While John has experienced depression off and on throughout his life, it only became severe in recent weeks," Fetterman's chief of staff, Adam Jentleson, said in a statement.

"After examining John, the doctors at Walter Reed told us that John is getting the care he needs, and will soon be back to himself," Jentleson said in that statement released Thursday afternoon.

But Fetterman's return to the Senate will not be a matter of days.

"We're looking at a few weeks" of inpatient care, as doctors try different medications and dial in the correct dosages, a senior Fetterman aide told NBC News on Thursday night. A top staffer for the senator confirmed that timeline to CNBC.

Fetterman's absence from Capitol Hill will temporarily narrow Democrats' slim 51-49 Senate majority, potentially making it harder for the polarized chamber to accomplish its goals. Congress is working to craft a bill to raise the U.S. debt ceiling before the summer and prevent the country from defaulting on its obligations, among other legislative priorities. The Senate is not in session next week.

Fetterman missed votes on Capitol Hill on Wednesday night and Thursday, NBC reported.

Fetterman's latest hospitalization prompted an outpouring of support from his political allies. Many of them praised the senator for being open about his struggle with depression, which still carries a stigma in the U.S.

"John, Gisele – Jill and I are thinking about your family today," President Joe Biden tweeted Friday.

"Millions of people struggle with depression every day, often in private. Getting the care you need is brave and important. We're grateful to you for leading by example," the president said.

Depression is a common experience after a stroke. Fetterman's aide told NBC that the senator has struggled to adjust to his current situation, leading him to seek treatment.

Fetterman's fundraising team sent an email Friday asking supporters to make a split donation to the National Alliance on Mental Illness and the Pennsylvania Mental Health Consumers' Association.