Bethenny Frankel, de Lesseps' "Real Housewives of New York" co-star, issued a statement to People confirming the news.
"This weekend, Luann was surrounded by her girlfriends and decided -- with their support -- that in light of recent circumstances, it is the healthiest choice for her not to attend Tuesday's reunion taping so that she can continue in her healing process," Frankel said in her statement. "Luann is now surrounded by a core group of people who truly have her best interests at heart and who are working to make sure she gets the help she needs. Bravo has been very supportive of Luann during this time. It's a brave and honest decision by her, and everyone is rallying around her and wants the best for her."
A publicist for Frankel told CNN that de Lesseps authorized the statement.
"Bravo supports Luann's decision to focus on her health. She is part of the Bravo family and we continue to stand by her as she copes with this challenging situation," a network spokesperson told CNN via email. "At this time, we hope everyone will respect her privacy."
De Lesseps previously entered a treatment facility last year, following an arrest in Florida where she was charged with battery of an officer and disorderly intoxication, according to the Palm Beach County Sheriff's Office.
De Lesseps pleaded not guilty to the charges. A hearing in the case is scheduled later this month.