Learning motivation improvers

摘要

The present invention aims to provide antidepressants which are free from the problem of side effects and are excellent in safety. The present invention also aims to provide learning motivation improvers which are useful for improvement of learning motivation and can be ingested continuously. The present invention provides antidepressants and learning motivation improvers, each comprising a cyclic dipeptide with the 2,5-diketopiperazine structure as an active ingredient.