Heroes with Mental Disorders or Heroes with Mental Illnesses (heroic madmen) are heroes who suffers from disorders that mainly affect the personality and behavior of the Hero. Some Heroes with mental illness can be (but aren’t always) insane (like Buck from Ice Age, for example). The some of the more common mental disorders are amnesia, PTSD and depression. Examples can be;

•  Max Payne who suffers from depression.
•  Rorschach who has a Paranoid Personality Disorder. 
• Cloud Strife who suffers from PTSD.
• Angela Orosco who suffers from C-PTSD.
• Robin who suffers from amnesia.

These characters are often Tragic, since the trait of being mentally unstable is being unable hinders their growth, causes them struggles in their daily life and sometimes are unable to tell right from wrong should their illness be worse. Examples include Ryūko Matoi, Homer Simpson, Shoto Todoroki, Goku, Sinon and Joe Swanson.

Some can also be Pure Good if they have no corrupting factors and if their mental illness doesn't interfere with their moral agency and knowledge of right and wrong. Dory, Forest Gump and Melman are good examples for this.

Notes

• Not all heroes are mentally unstable when they first appear. While some are, others who were sane to begin with suffer experiences that causes their sanity to snap. The primary causes for this are prolonged abuse and humiliation. A severe-enough degree of fear can do it too, but less commonly.
• Please do not add dissociative heroes under this category as the category is a subtype of mentally disordered heroes and adding both categories on the same hero at once would be redundant.
• Non-humanoid entities and angels never count, regardless of how good they can be. To them, such acts are normal or a simple spiritual/cultural function.

• Category: Mentally Ill - Villains Wiki