Many of the nightmarish killings of recent memory, especially the bizarre family tragedies which seem to be occurring with increasing frequency, have been scientifically linked to a sleep disorder caused by commonly-used, but dangerous and addictive anti-depressant medications.

The sky darkened and lightning struck nearby as former President Bill Clinton, sheltered by an umbrella, spoke to commemorate the 13 killed and two dozen injured during the April 20, 1999 shooting rampage of two homicidal students.

While Clinton and others spoke of the obvious pain and suffering inflicted by Eric Harris and Dylan Klebold, no one addressed the most important question:  What actually caused the two high school students to turn into cold-blooded killers?  Yet, without addressing the cause of the tragedy, how can we possibly expect to prevent similar tragedies in the future?

The Columbine shooting and many other nightmarish killings have now been scientifically linked by experts to a freakish sleep disorder caused by the growing use of anti-depressant medications that affect the level of serotonin in the brain.

Shortly before the Columbine shooting, Eric Harris had been rejected by Marine Corps recruiters because he was under a doctor's care and had been prescribed an anti-depressant medication.  Harris was taking Luvox, an anti-depressant commonly used to treat patients with obsessive-compulsive disorder.

Luvox is in a class of drugs called selective serotonin reuptake inhibitors (SSRI).  Other SSRIs include Prozac, Paxil and Zoloft.  An estimated 10 million Americans take anti-depressant medications.

Mark Taylor, the first student shot at Columbine, brought a lawsuit against Solvay, the international pharmaceutical company that produces Luvox.  Taylor's 2001 lawsuit said Luvox had caused Harris to become manic, psychotic, and homicidal/suicidal and had brought about "emotional blunting,'' or a lack of inhibition.  Tayor's lawsuit also faulted Solvay for failing to warn of the "risks and dangers'' associated with the drug.

In early 1998, according to Taylor's lawsuit, Harris had taken Zoloft for two months, but soon became "obsessional."  Harris became obsessed with homicidal and suicidal thoughts "within weeks" after he began taking Zoloft, according to Dr. Tracy.  Due to his obsession with killing, Harris was switched to Luvox, which was in his system at the time of the shooting, according to his autopsy.  The change from Zoloft to Luvox is like switching from Pepsi to Coke, Dr. Tracy said.

"I didn't realize what an epidemic it was until I went with Dr. Tracy and heard all the testimony," Taylor said. Mark's mother, Donna, told AFP that she had seen "tarantulas on the ceiling" and "snakes coming out of my mouth," hallucinations she had suffered while taking Paxil. "Racing thoughts" had prevented her from sleeping and she had not recognized her closest family members when they entered her home.

A Mayo Clinic study, said to be the first systematic demonstration of the relationship between anti-depressants and a sleep disorder known as RBD was presented at a June 19 sleep disorder conference in Salt Lake City.  The Mayo study demonstrated that a link exists between the use of anti-depressant medications in young people and the onset of REM Sleep Behavior Disorder (RBD).

RBD is the freakish sleep disorder, described by Dr. Tracy, in which patients act out their dreams, which are often unpleasant and violent.

The acting out of nightmares results from a loss of normal muscle paralysis in REM (rapid eye movement) sleep, the dream stage of sleep.  The normal muscle paralysis prevents one from acting out a dream or nightmare.  RBD patients, however, generally act out their dreams in a defensive posture, as if fending off an attacker, says R. Robert Auger, M.D., Mayo Clinic sleep medicine specialist, psychiatrist and primary investigator.

Dr. Tracy greeted the Mayo study saying this is exactly what she has been warning about for 14 years.

Asked about the significance of the Mayo Clinic study on the discussion of the dangers of SSRI anti-depressants, Tracy said:  "It is extremely significant.  This is the disorder I have been saying for 14 years is the main cause of such out-of-character violent behavior in association with the use of anti-depressants.

"If someone has the ability to move and act out the nightmares they are having, anything can happen and it is generally the worst thing a person could imagine happening to them.  This is why the very best mothers are killing their children – it is their worst nightmare."

"What could be more terrible than to chemically induce first of all someone’s most horrifying nightmare and then sleepwalk? In this way the individual acts out the one thing that is the most terrifying thing to them," Tracy wrote in 2003.  "This is clearly why we have cases of such loving and caring mothers, like Andrea Yates, killing their children – that was her worst nightmare."

Anti-depressants are also thought to have played a role in the bizarre 1996 murder of JonBenet Ramsey, the 6-year-old who was found beaten and strangled in her Boulder, Colorado home.  Patsy Ramsey, the recently deceased mother of JonBenet, is suspected of having "strangled her daughter in a panic on Christmas night," according to Steve Thomas, the former police detective who spent two years investigating the killing. The unanswered question, however, is whether Patsy Ramsey was taking anti-depressant medications at the time of the killing.

After the killing, it was reported that both John and Patsy Ramsey were taking Prozac.  In an October 1998 deposition, Mr. Ramsey was asked if he was "under the influence of any medication or alcohol."

"No alcohol, certainly, but I've been under a doctor's care for almost two years now and take Prozac," Ramsey said.

Asked about the significance of the fact that the Columbine shooter Eric Harris was taking SSRI anti-depressants, Tracy said:  "It is very significant.  We know that Eric Harris had the same nightmare about killing kids at school at least three times before he acted it out at Columbine.  He even made the statement that he was going to stop his medication to 'fuel his rage.'"

Tracy told AFP that anti-depressants are extremely addictive and that extreme care must be taken when a user begins to wean him or herself off of the medication.  The dosage has to be reduced carefully and gradually and the weaning period should be about half the time the person has been on the medication.  Any abrupt changes in dosage can cause suicidal and homicidal reactions, Tracy said.

"Two years ago," she said, "the FDA issued warnings that abruptly changing the dose of the anti-depressant, whether going up or down in dose, can produce hostility, psychosis and/or suicide.

"The manufacturers of Luvox, along with the makers of Zoloft and Paxil, should be held largely, not partly, responsible for the shooting rampage at Columbine," Tracy said.  "Without these medications I do not believe Columbine would ever have happened."

Mark Taylor and Dr. Tracy worked with film-maker Michael Moore in a forthcoming documentary called The Drugging of our Children, which Tracy said should air on public television in the near future.

"In the documentary Michael [Moore] states that in the movie Bowling for Columbine they look at all the reasons people were saying Columbine happened and that none of those reasons made sense.  The only thing that makes any sense is the killers' use of anti-depressants, Moore said.

"How else do you take a perfectly normal, high-achieving child and turn them into murderous monsters almost overnight?" Moore asks.

"After 16 years of researching and testifying about these anti-depressant medications," Tracy said, "it is my opinion that he could not have stated it better."