Kate is survived by her husband Andy, who is the brother of actor David Spade and her 13-year-old daughter Frances.
Mr Spade said the designer was seeing a doctor on a regular basis and taking medication for depression and anxiety.
Spade was found dead in her NY apartment yesterday after taking her own life, aged 55.
Saffo and other members of the Spade family tried in vain to get Kate help, but she says that, ultimately, Kate's pain was too great.
David Spade has taken to his social networking sites to remember his sister-in-law Kate Spade after she was found dead at her home in NY this week in a suspected suicide. "It was a complete shock", he said.
Andy Spade called his wife the kindest person he knew and said he can not fathom life without her.
"We ate many meals together as a family and continued to vacation together as a family", Andy says.
Local media reported that the death appeared to be a suicide by hanging and that Spade was found by a housekeeper.
Kate Spade speaks to the crowd during an event at Hall's on Grand at Crown Center Plaza on Wednesday, March 9, 2016 in Kansas City, Mo.
NY rapper Foxy Brown is sending some heartfelt words in the memory of fashion icon Kate Spade. "She was exceedingly kind, beautifully sensitive, insanely talented, amusing as heck and one of the most generous people I have ever known". She launched a new fashion brand in 2007, Frances Valentine after leaving Kate Spade New York.
In the 25 years since Kate Spade's founding of her handbag line, the name has become a byword for a certain preppy style.
Saffo also released a statement where she wrote that Spade was a precious person and genuine in every way.
There were media reports that Kate Spade left a suicide note.
The luxury fashion company Coach announced it was purchasing the company for $2.4 billion past year.
Chillingly, Saffo added: "One of the last things she said to me was, 'Reta, I know you hate funerals and don't attend them, but for me would you PLEASE come to MINE, at least".
"For us, these bags were not simply versatile enough to go from boardroom to bar (as they were for numerous working women in our orbit), they were our first portal into the unfamiliar, intoxicating world of fashion", the magazine explained.