 In 2006, Marnie Schulenburg was cast in the role; she made her debut when the character made a crossover appearance on "The Young and the Restless" on February 22, 2007, and later debuted on "As the World Turns" the following month.Schulenburg remained with the soap until its final episode on September 17, 2010, becoming the longest-tenured actor in the role.Alison was introduced on July 11, 1994, Susan Stewart and her much younger husband, fellow doctor Larry McDermott.