Senator John Fetterman, Democrat of Pennsylvania, checked himself into Walter Reed National Military Medical Center on Wednesday night to receive treatment for clinical depression. His chief of staff, Adam Jentleson, said in a statement that Mr. Fetterman had been experiencing depression off and on throughout his life, but had only become severe in recent weeks. Mr. Fetterman, 53, had previously been hospitalized last week after feeling lightheaded.

Dr. Brian P. Monahan, the attending physician in Congress, had recommended Mr. Fetterman bear inpatient care at the Walter Reed National Military Medical Center. In the statement, Mr. Jentleson said that the doctors there had told him that Mr. Fetterman was receiving the care he needs and would soon be back to himself.

Senator Fetterman was elected in November of last year after suffering a near-