Characterize is a type of Distinguish. Distinguish is related to Mental. Mental is related to Depression. Depression can cause/lead to Suicide. 
Vital is related to Necessary. Necessary is related to Necessity. 
Characterize --IsA--> Distinguish <--RelatedTo--> Mental <--RelatedTo--> Depression --Causes--> Suicide 
Vital <--RelatedTo--> Necessary <--RelatedTo--> Necessity 