The New York City medical examiner’s office said Thursday that the death of Kate Spade, the designer who was found in her apartment this week, was a suicide.

Ms. Spade, 55, had suffered from severe depression, her husband, Andy Spade, said Wednesday.

The designer, with her husband and business partner, built an accessories empire off an idea about a handbag that resonated deeply with many women for almost three decades.

Long after Ms. Spade and her husband left their company to devote themselves to other projects, they launched a new venture in 2016, an accessories label called Frances Valentine.

[If you are having thoughts of suicide, call the National Suicide Prevention Lifeline at 1-800-273-8255 (TALK) or go to SpeakingOfSuicide.com/resources for a list of additional resources.]