Learning motivation improvers

Abstract

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.

1 . An antidepressant comprising a cyclic dipeptide with the 2,5-diketopiperazine structure as an active ingredient. 
     
     
         2 . The antidepressant according to  claim 1 , wherein the cyclic dipeptide is one or more members selected from the group consisting of 2,5-piperazinedione,3,6-bis(phenylmethyl)-,(3S,6S), pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(1H-imidazol-4-ylmethyl)-,(3S,8aS), and pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(1H-indol-3-ylmethyl)-, (3S,8aS). 
     
     
         3 . The antidepressant according to  claim 2 , which further comprises one or more members selected from the group consisting of 2,5-piperazinedione,3,6-bis(1H-indol-3-ylmethyl)-,(3S,6S), pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(2-methylpropyl)-,(3S,8aS), and pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(1-methylethyl)-,(3S,8aS). 
     
     
         4 . The antidepressant according to  claim 1 , which is for oral administration. 
     
     
         5 . The antidepressant according to  claim 1 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         6 . A learning motivation improver comprising a cyclic dipeptide with the 2,5-diketopiperazine structure as an active ingredient. 
     
     
         7 . The learning motivation improver according to  claim 6 , wherein the cyclic dipeptide is 2,5-piperazinedione,3,6-bis(phenylmethyl)-,(3S,6S). 
     
     
         8 . The learning motivation improver according to  claim 6 , which is for oral administration. 
     
     
         9 . The antidepressant according to  claim 2 , which is for oral administration. 
     
     
         10 . The antidepressant according to  claim 3 , which is for oral administration. 
     
     
         11 . The antidepressant according to  claim 2 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         12 . The antidepressant according to  claim 3 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         13 . The antidepressant according to  claim 4 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         14 . The antidepressant according to  claim 9 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         15 . The antidepressant according to  claim 10 , which is a prophylactic and/or therapeutic agent for depression, senile depression symptoms, depressed mood, hypobulia, anxiety, or insomnia or anorexia associated with these symptoms. 
     
     
         16 . The learning motivation improver according to  claim 7 , which is for oral administration.