Method for alleviating fear memory

Abstract

The present invention provides new methods of intervention for anxiety associated disorders, in particular, trauma-derived disorders such as PTSD, and therapeutic or prophylactic agents for anxiety associated disorders that can be used as foods, beverages, and dietary supplements, for example, and which contain as an active ingredient n-3 polyunsaturated fatty acids contained in krill oil or fish oil, for example. The present invention further provides methods for alleviating fear memory or methods for preventing its formation by adjusting the proportion of n-3 polyunsaturated fatty acids to n-6 polyunsaturated fatty acids as ingested.

1 . A method of treating a human suffering from, or preventing a human from suffering from, post traumatic stress disorder comprising administering to said human an n-3 polyunsaturated fatty acid in an effective amount within a safe range to treat or prevent the post traumatic stress disorder in said human, wherein administration of an n-6 polyunsaturated fatty acid is restricted, and wherein the human received a traumatic stress. 
     
     
         2 . The method according to  claim 1 , wherein the weight ratio of the n-3 polyunsaturated fatty acid to the n-6 polyunsaturated fatty acid as administered is at least 0.8. 
     
     
         3 . The method according to  claim 1 , wherein the n-3 polyunsaturated fatty acid and/or n-6 polyunsaturated fatty acid is either an unsaturated fatty acid derived from a constituent fatty acid in a lipid or an unsaturated fatty acid derived from an C 1-6  alkyl ester of the n-3 polyunsaturated fatty acid and/or n-6 polyunsaturated fatty acid. 
     
     
         4 . The method according to  claim 1 , wherein the n-3 polyunsaturated fatty acid is at least one n-3 polyunsaturated fatty acid selected from the group consisting of α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. 
     
     
         5 . The method according to  claim 1 , wherein the n-3 polyunsaturated fatty acid is eicosapentaenoic acid or docosahexaenoic acid. 
     
     
         6 . The method according to  claim 1 , wherein the n-6 polyunsaturated fatty acid is at least one n-6 polyunsaturated fatty acid selected from the group consisting of linoleic acid, γ-linolenic acid, eicosadienoic acid, dihomo-γ-linolenic acid, arachidonic acid, docosadienoic acid, and adrenic acid. 
     
     
         7 . The method according to  claim 1 , wherein the n-6 polyunsaturated fatty acid is linoleic acid or arachidonic acid. 
     
     
         8 . The method according to  claim 3 , wherein the lipid is one derived from krill oil or fish oil. 
     
     
         9 . The method according to  claim 1 , wherein the subject suffering a posttraumatic stress disorder is diagnosed by a method comprising measuring the weight ratio in blood of an n-3 polyunsaturated fatty acid to an n-6 polyunsaturated fatty acid, and determining that the subject is a low-risk subject if measured weight ratio is greater than a reference value, wherein the reference value is any one selected from values of 0.8 and greater. 
     
     
         10 . The method according to  claim 9 , wherein the n-3 polyunsaturated fatty acid is at least one n-3 polyunsaturated fatty acid selected from the group consisting of α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. 
     
     
         11 . The method according to  claim 9 , wherein the n-3 polyunsaturated fatty acid is eicosapentaenoic acid or docosahexaenoic acid. 
     
     
         12 . The method according to  claim 9 , wherein the n-6 polyunsaturated fatty acid is at least one n-6 polyunsaturated fatty acid selected from the group consisting of linoleic acid, γ-linolenic acid, eicosadienoic acid, dihomo-γ-linolenic acid, arachidonic acid, docosadienoic acid, and adrenic acid. 
     
     
         13 . The method according to  claim 9 , wherein the n-6 polyunsaturated fatty acid is linoleic acid or arachidonic acid. 
     
     
         14 . The method according to  claim 9 , wherein the fatty acids are ones obtained from a blood sample.