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Ethan Couch, the Texas teen who used an "affluenza" defense in a fatal drunk driving accident, has officially dropped his appeal against deportation, his Mexican attorney said.

"I believe (Ethan) is relieved to be coming back," Fernando Benitez told NBC News. "I think he has come to terms with this."

Couch, 18, fled the country while serving 10 years of probation for a drunken driving crash that killed four people in 2013. He and his mother were captured in Mexico last month. His mother, Tonya, was deported to the U.S., but Couch remained detained in Mexico City. Tonya Couch was released after posting bail.

Couch's extradition could happen as early as Wednesday.

Related: Tonya Couch Is Allegedly Broke, Has Bond Reduced

"He decided that he would much rather face American justice than drag it out here in Mexico," Benitez said.

During Couch's trial for the fatal car accident, a defense witness said his wealthy parents coddled him so much, it gave him no sense of responsibility — a condition the expert referred to as "affluenza." That condition isn't recognized as a diagnosis by the American Psychiatric Association.