"She was actively seeking help for depression and anxiety over the last five years, seeing a doctor on a regular basis and taking medication for both depression and anxiety," her husband Andy Spade said in a statement carried by The New York Times. 

It was a blunt rebuke to claims by the designer's sister that Kate Spade needed mental health care but refused treatment over concerns about potentially hurting the light-hearted brand.

The death of the 55-year-old star designer, whose body was found Wednesday in her Park Avenue apartment, "was not unexpected by me," Spade's older sister Reta Saffo told The Kansas City Star from her home in Santa Fe, New Mexico.

Spade -- a Missouri native who first worked as a journalist, including a stint as accessories editor at Mademoiselle magazine -- launched her Kate Spade fashion label in 1993 with her husband Andy and the help of outside investors.

Her cheerful use of bright colors and prints proved a hit with career women. Over a decade ago, she sold the business and later launched a luxury line Frances Valentine.

Celebrity news website TMZ cited police sources as saying Spade had fallen into depression in recent weeks after her husband left her and was seeking divorce.

Andy Spade said that the couple had been living apart but in the same neighborhood, caring for their 13-year-old daughter Bea.

Read also: US designer Kate Spade dead at 55 in apparent suicide

- Embodying authenticity -

"Our daughter was our priority. 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," Andy Spade added.

"There was no substance or alcohol abuse. There were no business problems. We loved creating our businesses together. We were co-parenting our beautiful daughter," he stressed.

"My daughter and I are devastated by her loss, and can't even begin to fathom life without her."

Anna Wintour, the grand priestess of fashion and editor-in-chief of Vogue magazine, hailed Spade as a woman who "defined" authenticity.

"There was a moment when you couldn't walk a block in New York without seeing one of her bags, which were just like her; colorful and unpretentious," Wintour said in a statement.

"Kate designed with great charm and humor, and built a global empire that reflected exactly who she was and how she lived. Long before we talked about 'authenticity,' she defined it."

Several admirers such as First Daughter Ivanka Trump highlighted the importance of suicide helplines and seeing the signs of depression.

"Kate Spade's tragic passing is a painful reminder that we never truly know another's pain or the burden they carry. If you are struggling with depression and contemplating suicide, please, please seek help," Trump tweeted.