The treatment to restore mentally unfit defendants to competence so that they can stand trial for heinous crimes is an uncertain science that, in a number of high-profile cases, has taken years — and at times failed altogether.

Legal and medical experts said the odds are good that Jared Lee Loughner, 22, ruled incompetent by a federal judge this week, will recover though antipsychotic drugs and ultimately face charges in the Jan. 8 shooting spree in Tucson that killed six and wounded Rep. Gabrielle Giffords (D-Ariz.) and 12 others. But the experts also cautioned that significant pitfalls could prevent a speedy trial.

Each year, an estimated 10,000 to 12,000 defendants across the country have their trials delayed after being found mentally incompetent. Roughly 75 percent are successfully rehabilitated within six months, according to several published studies.

Those who do not recover quickly, however, often remain in a lengthy state of limbo, even though the U.S. Supreme Court has ruled that defendants cannot be held indefinitely. For example, Lucas John Helder, 30, accused of planting bombs in 18 mailboxes across the Midwest in 2002, has remained in a federal medical facility in Rochester, Minn., since April 2004, when a judge found him incompetent.

“There is a subset that for various reasons do not respond,” said Kirk Heilbrun, chairman of Drexel University’s psychology department, who has worked with juvenile and adult offenders. “They don’t respond as well to the medication, or it’s not the right medication or dosage. There could be issues about their motivation, such as they exaggerate or fabricate symptoms, and it can be hard to document.”

Loughner’s treatment

Mental incompetence, unlike an insanity defense, is based on the defendant’s state of mind heading into a trial. An insanity defense focuses on his mental health leading up to the crime and during it. Legal experts said they expect Loughner’s attorneys to present an insanity defense if he goes to trial. But such cases are rarely successful and have become even more difficult since Congress tightened the insanity-defense standards after John Hinckley Jr., who shot President Ronald Reagan, was found not guilty in 1982.

For the next four months, Loughner will spend his nights in a sparsely furnished cell at the 300-inmate psychiatric wing of the U.S. Medical Center for Federal Prisoners in Springfield, Mo. U.S. District Judge Larry A. Burns, who ruled Loughner mentally unfit, has set a Sept. 21 date in a Phoenix federal courthouse to determine whether he has recovered or is making enough progress to continue the rehabilitation.

Physicians will seek to administer drugs such as Abilify, Seroquel, Risperdal or Geodon to control his diagnosed schizophrenia and staff psychologists and psychiatrists will work with Loughner daily, said David Mrad, a forensic psychologist who worked at the Springfield facility for 24 years before retiring in 2006.

If Loughner refuses to take the medicine voluntarily, federal prosecutors will probably petition the court to order forcible injections. A court battle could drag out for months if Loughner’s public defenders objected, experts said.

Attorneys for Russell Eugene Weston Jr., who allegedly shot and killed two Capitol Police officers in 1998, fought for three years before the D.C. Circuit court ruled in 2001 that he could be forcibly medicated. In 2003, the Supreme Court imposed strict limits on forced drugging, ruling that courts could do so only when inmates are a danger to themselves or others and if it is in their best interest.

“They’ll have to show that the treatment is likely to be effective and not have side effects that would interfere with the ability to stand trial,” said Ronald Roesch, director of the Mental Health, Law and Policy Institute at Simon Fraiser University in Vancouver, B.C. “One concern is that the antipsychotic medication could [make an inmate] go back to court and just sit there and not care about anything.”

Even if Loughner is medicated, there is no guarantee the drugs will work. Thirteen years after his crime, Weston — who told psychiatrists he stormed the Capitol to prevent the United States from being annihilated by legions of cannibals — remains at a medical facility, having yet to face charges.

Patricia Zapf, an associate professor of forensic psychology at John Jay College in New York, said defendants who fail to recover their mental competence usually fall into two categories: those with a severe brain injury or mental retardation and those who have exhibited a long history of severe mental illness.

Roughly 50,000 to 60,000 inmates are evaluated for mental incompetence each year, and their mean age is 36, Zapf said. But the first sign of psychotic problems usually occurs in males in their late teens or early 20s, she said.

“There are a lot of effective medications out there,” she said. “They’ll try as many different medications as possible. But for some people, the medications just don’t work.”

Supreme Court ruling

In a landmark 1972 case, Jackson v. Indiana, the Supreme Court ruled that defendants ruled mentally unfit cannot be held for long periods of time, such as beyond the length of a prison sentence had they been convicted.

The only exceptions are in cases where the inmate is considered dangerous. Federal prosecutors said Loughner, who is alleged to have fired 31 rounds from a Glock 19 semiautomatic pistol, is a clear danger and will not be set free.

Simply assessing Loughner’s response to treatment might prove difficult.

Brian David Mitchell, accused of abducting and raping 14-year-old Elizabeth Smart in Utah in 2002, was found incompetent in July 2005 and again in December 2006, based on expert testimony that he was a paranoid schizophrenic.

It was not until 2010, after federal prosecutors took over the case from the state, that Mitchell was declared competent and eventually found guilty. Federal lawyers relied on analysis from Michael Welner, a New York psychiatrist who spent six months examining the case.

Welner determined that Mitchell, who sang through his court proceedings and spouted pseudo-religious gibberish, was a skilled con man who was largely faking his delusions.

“Psychiatry is far less able to detect faking than it asserts,” Welner said in an interview this week. “Experience teaches me that an ounce of fact is worth a pound of expertise.”

Mitchell was sentenced to life in prison on the same day Loughner was found incompetent.