Abstract: The present invention relates to a composition for preventing or treating neuropsychologic diseases, the composition including placental growth factor (PLGF), or a peptide derived therefrom or a fragment thereof. The administration of the PLGF according to the present invention promotes the differentiation of GABAergic (?-aminobutyric acid, GABA) nerve cells in a memory impairment and autism model to induce nerve regeneration, to enhance memory ability and to ameliorate decline in social cognition, sociability and social sexual preference, whereby a composition for preventing or treating neuropsychologic diseases such as autism, ADHD, mental retardation disorder, and developmental disorder can be provided.

Abstract: The present invention relates to a composition for preventing or treating neuropsychologic diseases, the composition comprising a mesencephalic growth factor (mesencephalic, astrocyte-derived neurotrophic factor; MANF), a peptide derived therefrom or a fragment thereof. The administration of the MANF according to the present invention promotes the differentiation of cholinergic and/or GABAergic (?-aminobutyric acid) nerve cells in models of memory impairment and autism to induce nerve regeneration, exhibits the effects of enhancing memory and ameliorating emotional anxiety, and ameliorates social cognition, sociability and decline in social sexual preference, whereby a composition for preventing or treating neuropsychologic diseases such as autism, ADHD, mental retardation disorder, and developmental disorder can be provided.