Benicio Del Toro and Mathieu Amalric were the only actors that director Arnaud Desplechin wanted for his new movie, he has said.
The filmmaker has revealed that he wouldn't have made Jimmy P if Benicio and Mathieu hadn't signed up.
"I thought if I can't have them, I won't do the film," he said.
In Jimmy P (Psychotherapy Of A Plains Indian), Mathieu plays real-life French analyst Georges Devereux, who moved to the United States in the 1930s. He spent time living with Mojave Indians and helped develop the field of ethno-psychiatry, which studies the ways mental illness is understood in different cultural contexts.
Benicio is his patient Jimmy Picard, who returned from World War II in France with a head injury and debilitating psychological symptoms his doctors were unable to diagnose.
Director Arnaud said it's the first time he has written a film with actors already in mind.
"I was so nervous when I started it because it was quite difficult to produce because the film is half French, half American, so it was quite tricky," he said.
"So before writing it I was thinking who could play in that? I wrote it really for Benicio and Mathieu, they were the two guys."