His mother is the Hungarian-born photojournalist Sylvia Plachy, and he attended the American Academy of Dramatic Arts and High School for the Performing Arts. Adrien grew up an only child in Woodhaven, Queens, where he accompanied his mother on assignments for the Village Voice. He credits her with making him feel comfortable in front of the camera.
Despite a strong performance in The Thin Red Line, the film's time constraints forced the director to edit out much of Adrien's parts and despite his later work with Spike Lee and Barry Levinson, he never became the star many expected he would become...until Roman Polanski called on him to play a celebrated Jewish pianist in the Nazi-occupied Warsaw. He pulled off a brilliant performance in "The Pianist" drawing on the heritage (and rare dialect) of his Polish grandmother.