The present invention provides a fusion protein of BDNF and an anti-human transferrin receptor antibody, in which in a heavy chain variable region of the antibody, (a) CDR1 includes an amino acid sequence of SEQ ID NO: 66 or SEQ ID NO: 67, (b) CDR2 includes an amino acid sequence of SEQ ID NO: 13 or SEQ ID NO: 14, and (c) CDR3 includes an amino acid sequence of SEQ ID NO: 15 or SEQ ID NO: 16.