Director Paul Schrader shared details of his decision making process in casting Lindsay in the role of Tara on The Canyons’ official Facebook page:

‘Lindsay Lohan came late to the casting of Tara. I had originally planned to cast Monica Gambee, a model who posted her audition on letitcast. I was surprised how solid her reading was. After Braxton Pope met with her in Los Angeles, I flew out to screen test her. He laid out our situation (in terms of script, budget, nudity) and it seemed like we’d found our Tara. But when Monica heard that we were also considering James Deen, she balked at doing the test. I notified her that I would be willing not to consider Deen if she would be the lead (James had not yet tested), but Monica’s process of indecision was already in motion. It then became one thing one thing after another, and finally, she never came in for the screen test. I had planned that weekend to cast her both her and Sean Brosnan as the leads, but that plan unravelled

Source Hollywood Backwash