Lewis has broken her silence following the publication of a New York Times expose last week, in which seven women, including Adams' ex-wife Mandy Moore and former fiancee, spoke out about alleged sordid experiences with the star.
One of the women was a minor when she reportedly started receiving explicit correspondence from the New York, New York singer.
Lewis, who worked with Adams on her last album "The Voyager" and upcoming record "On the Line", has taken to social media to address the controversy, writing: "I am deeply troubled by Ryan Adams' alleged behaviour. Although he and I had a working professional relationship, I stand in solidarity with the women who have come forward".
"This Is Us" star Moore alleged that her ex was ''psychologically abusive'' towards her and mocked her musical talents throughout their marriage, insisting, "His controlling behavior essentially did block my ability to make new connections in the industry during a very pivotal and potentially lucrative time - my entire mid-to-late 20s... Music was a point of control for him".
But the most troubling piece of the Times article was the accusations of a woman named Ava, who was 14 when she started corresponding with Adams online, and was 15 when he allegedly started sending her explicit photos and notes.
Adams has dismissed all the allegations but apologised if any of his actions made any woman feel uncomfortable.
In a tweet posted last week, he wrote: "I am not a perfect man and I have made many mistakes. To anyone I have ever hurt, however unintentionally, I apologize deeply and unreservedly. But the picture that this article paints is upsettingly inaccurate. Some of its details are misrepresented; some are exaggerated; some are outright false".
I am not a perfect man and I have made many mistakes. To anyone I have ever hurt, however unintentionally, I apologize deeply and unreservedly.— Ryan Adams (@TheRyanAdams) February 13, 2019
His lawyer, Andrew Brettler, added: ''Mr. Adams unequivocally denies that he ever engaged in inappropriate online sexual communications with someone he knew was underage".