Former Miss USA Cheslie Kryst's mother said she had high-functioning depression. Here's what that means.

• Former Miss USA Cheslie Kryst's new memoir was finished by her mother, April Simpkins. 
• Simpkins discussed Kryst's struggle with high-functioning depression before her death in 2022. 
• The term describes depression among people who maintain happy-looking, productive lives. 

A new memoir by former Miss USA Cheslie Kryst was released on Tuesday. "By the Time You Read This" was finished by her mother, April Simpkins, who said it was one of her daughter's final wishes.