Mr. Spade rebutted reports that it was Mr. Spade’s desire to end his marriage that caused his wife’s depression. “We were not legally separated, and never even discussed divorce. We were best friends trying to work through our problems in the best way we knew how. We were together for 35 years. We loved each other very much and simply needed a break,” he said.

Ms. Spade’s older sister, Reta Saffo, told the Kansas City Star that Ms. Spade’s suicide was “not unexpected” and that her sister had refused to get treatment for her depression because of fear it might damage her brand.

However, Ms. Spade’s older brother, Earl Brosnahan, said Ms. Saffo had been estranged from the rest of the family for more than 10 years, to the extent that she had not attended their mother’s funeral in 2010. (Ms. Saffo did not respond to messages left at her home number.) Though he acknowledged Ms. Spade had been in sporadic contact with Ms. Saffo in recent years — the only one of the six siblings to speak to Ms. Saffo — he said he was taken aback that Ms. Saffo “should surface now with very definitive statements that I think are grossly inaccurate” and attributed the contact between them to Ms. Spade’s personality.

“It was Katy’s way to be accessible and available to everyone,” he said.

Both Mr. Brosnahan and Elyce Arons — Ms. Arons became close friends with Ms. Spade as an 18-year-old at the University of Kansas and later became her business partner in both Kate Spade and Frances Valentine — said they had been aware of Ms. Spade’s depression and the separation in her marriage.

Mr. Brosnahan said he and Ms. Spade had discussed “her sadness, which is what we liked to call it.” He said he became aware of it about 18 months ago. Though he said he and his sister often spoke several times a day, it sometimes became difficult to get her on the phone. He said he had dinner with her a week before her death, and “she was still talking very much about the future and collaborating with Andy on projects for Frances Valentine.”