© LM Otero/APEthan Couch in court in Fort Worth, Texas, where Judge Jean Boyd again decided against sending him to jail.
The Texas teenager who avoided prison after a psychologist described him as suffering from "affluenza" has been ordered by a judge to attend an undisclosed rehabilitation facility.

Ethan Couch was given ten years' probation last December for killing four people and seriously injuring two while driving drunk. On Wednesday, district judge Jean Boyd again did not issue any jail time and assigned him to the centre in a court hearing that was closed to the media.

The sentence handed out by Boyd last year outraged the victims' families and the case attracted national attention after a psychologist called by the defence testified that the teenager had "affluenza", indicating that his behavioural problems were influenced by a troubled upbringing in a wealthy family where privilege prevented him from grasping the consequences of his actions.

Critics said the outcome was an egregious example of a justice system that treats the rich and the poor differently.

A statement from the Tarrant County district attorney's office said that the judge "ordered the teen be placed in a lock-down residential treatment facility, where he will remain for an undisclosed period. She ordered his parents to pay for the cost of his treatment."

As a condition of his probation, the teen is not allowed to drive and must refrain from any alcohol and drug use, among other things. If he violates any condition of his probation over the next ten years, he could be sentenced to up to ten years behind bars."

Prosecutors had originally asked Boyd to sentence Couch to 20 years' detention, while his lawyers recommended his parents pay for him to seek therapy at a $450,000-a-year rehabilitation facility in California.

Wednesday's hearing was scheduled after prosecutors once more tried to argue he should go to prison, this time as punishment for charges related to the two injured people.

Couch, from Keller, near Fort Worth, admitted four counts of intoxication manslaughter. He was speeding last June when he lost control of his Ford F-350 pick-up truck, swerved off a suburban road and ploughed at up to 70 mph into a group of people who were helping Breanna Mitchell, whose car had broken down.

Mitchell, a youth pastor named Brian Jennings, Hollie Boyles, and her daughter, Shelby, were killed.

Couch had seven passengers. Two were riding in the bed of the truck and were seriously injured. One is paralysed and unable to speak. The other suffered broken bones and internal injuries.

Lawsuits seeking damages from Couch and his family have been filed by several of the victims' relatives.

Aged 16 at the time, Couch's blood alcohol level was three times the adult legal limit and there were traces of Valium and other drugs in his system, according to prosecutors, who said the group had stolen beer from a Walmart.

"Money always seems to keep [him] out of trouble. Ultimately today, I felt that money did prevail," Eric Boyles, husband to Hollie and father of Shelby, told the Fort Worth Star-Telegram after the trial.

The psychologist, G Dick Miller, told CNN he wished he "hadn't used that term. Everyone seems to have hooked on to it. We used to call these people spoiled brats."

"Affluenza" is not a condition recognised by the American Psychiatric Association. The term was coined as far back as the 1950s and popularised in the late 1990s, when it referred to the stress caused by obsessive consumerism.

Last month, Mike Gatto, a California assemblyman, proposed a bill banning the "affluenza defence" from being used in the state's courts. "I just think it really is one of those times where unless we're proactive it could become something that's far more common," he said.