Term is related to Health. Health is related to System. System is related to Operating. 
Depressed is a synonym of Unhappy. Unhappy is a synonym of Low. Low is related to Short. 
Term <--RelatedTo--> Health <--RelatedTo--> System <--RelatedTo--> Operating 
Depressed <--Synonym--> Unhappy <--Synonym--> Low <--RelatedTo--> Short 