(CNN) Amber Heard has outlined the abuse she says she experienced by her former husband, Johnny Depp, as she fights a $50 million defamation suit he has filed against her.

In an affidavit obtained by CNN and included in Heard's motion to have the case against her dismissed, the actress alleges that a year into their relationship, she began to witness the "Pirates of the Caribbean" star abusing drugs and alcohol.

"Whenever he was using I worried for both of us," Heard stated in the filing. "He would become a totally different person, often delusional and violent. We called that version of Johnny, 'the Monster.'"

The court documents detail multiple instances of alleged abuse in which Heard claims that Depp hit her, threw bottles, yelled at her, shoved Heard, pulled out chunks of her hair and at one point strangled her.

"I remember being afraid that Johnny might not know when to stop, and that he might kill me," Heard said in the filing.

Read More