People battle depression and personal demons and sometimes it takes over (regardless of how successful others may perceive you to be). I am very sorry this happened. My condolences to her friends and family.
AoSHQ: Kate Spade: Depression Suicide
Hollywood Reporter: Kate Spade, dead at 55
Variety: Celebrities React to Kate Spade's Death
PJ Media: Thoughts on Kate Spade, Depression and Suicide
EBL: Rachel Brosnahan: The Marvelous Mrs. Maisel (she was Kate Spade's niece)
IOTWR: Mentally ill Bradley Manning says first responders to his suicide threats are 'police state'
People do care: National Suicide Prevention Lifeline is available 24/7 at 1-800-273-TALK (8255)