Elizabeth Vargas Leaves ABC News

After 22 years with ABC News, Elizabeth Vargas is leaving the news organization.

Multiple sources told DailyMail.com that the longtime 20/20 co-anchor will be stepping down in May, when the news broadcast show wraps its 40th season.

"I want you to hear some news about me, from me," she wrote in a note to her co-workers. "I will be leaving ABC News, and 20/20 at the end of this historic 40th season. It has been a profound privilege to be the anchor of 20/20 for 14 years, and a true honor to work with each and every one of you. I am incredibly lucky to work alongside the very best in the business: the producers, editors, writers on this show, and the enormous team working every week to get our show on the air. I am so very proud of the stories we have told together."

"I am sorry only to have to share this news with you as we celebrate the holidays. I had hoped to make this announcement after the first of the year," she continued. "This is not goodbye — I will be here through May, and cannot wait to do more work with all of you in the months ahead."

ABC News president James Goldston revealed in a gushing memo to staff, obtained by Variety, that the exit was Vargas' choice in order "to pursue new ventures."

"From co-anchor of 'World News Tonight' to news anchor for 'GMA,' Elizabeth has served in many key roles here and won nearly every award in broadcasting along the way. But we were most proud of her courage and grace in telling her own story about her struggle with anxiety and alcoholism. Her best-selling memoir has helped so many people by raising awareness about the importance of finding treatment for millions who are still struggling. She continues to be an inspiration for us all."

The 55-year-old journalist has spent 14 seasons on 20/20 and has appeared on Good Morning America and World News Tonight.

Vargas got her start at a CBS affiliate in Chicago before making the leap to NBC News in 1993, where she worked as a correspondent for Dateline and occasionally filled in on Today.

She joined ABC in 1996 as a news reader on Good Morning America, and quickly joined the primetime lineup the following year with her role as the anchor on World News Tonight on Saturday.

In 2004, she was named co-anchor on 20/20 and then in 2005 was named co-anchor of World News Tonight. She stepped down from her World News Tonight position in May 2006, citing a difficult pregnancy, and did not return to her position after her maternity leave.

In January 2014, she opened up about her struggle with alcoholism after doing a stint in rehab in 2013.

"I am an alcoholic," she revealed on Good Morning America. "It took me a long time to admit that to myself. It took me a long time to admit it to my family, but I am," she said. "The amount of energy I expended keeping that secret and keeping this problem hidden from view was exhausting."

Vargas completed another stint in rehab in August 2014.