Provided is a therapeutic agent for a neurological disorder directly acting on oxygen concentration-dependent vascular barrier breakdown. The therapeutic agent for a neurological disorder contains any one of (a) a functional nucleic acid against ADAM (a disintegrin and metalloproteinase)12 or ADAM17, (b) a functional nucleic acid expression vector containing a DNA encoding the functional nucleic acid (a) and (c) a neutralizing antibody against ADAM12 or ADAM17, as an active ingredient. The functional nucleic acid is preferably siRNA. It is preferable that the functional nucleic acid against ADAM12 is siRNA consisting of a sense strand sequence of nucleotides represented by SEQ ID NO: 1 or 3 and an antisense strand sequence complementary thereto or that the functional nucleic acid against ADAM17 is siRNA consisting of a sense strand sequence of nucleotides represented by SEQ ID NO: 5 or 7 and an antisense strand sequence complementary thereto.
