Supernatural (2005)

S5E11 Sam, Interrupted

Martin, a former hunter now confined to a mental institution, reaches out to Sam and Dean for assistance with a troubling case involving a creature that is preying on patients. To uncover the truth, the brothers voluntarily check themselves into the facility. However, their experience inside the hospital tests their limits, as the pressures of confinement lead them to confront their own inner demons, resulting in a volatile clash between them.