WASHINGTON — For more than two centuries, explorers, travelers and researchers have tracked the disturbing phenomenon of individuals who act out their rage against the world in an abrupt burst of homicide against total strangers. Invariably, the violence ends with the person getting killed or taking his own life.

The rare and little understood phenomenon has been called amok or running amok, a phrase derived from the Malay word mengamok, which means "to do furious battle." This week, several experts said Seung-Hui Cho's shooting rampage at Virginia Tech reminded them of a long list of other amok cases.

Thinking of Cho's behavior in the context of amok is one of many ways mental health experts have been struggling to make sense of the Virginia Tech tragedy. More conventional explanations have suggested he might have been suffering from a psychotic disorder or personality problems — one practitioner's diagnosis in 2005 suggested Cho was depressed.

Experts who consider the Cho case an example of amok are not suggesting it is a competing diagnosis as much as a way to describe a pattern of behavior. For the better part of two centuries, Western observers thought the phenomenon was limited to "primitive" cultures in Asia, the Caribbean and native America, but this notion has been demolished in recent years. Those who study amok say it now occurs mainly in Western countries.

"The truth of the matter is this occurs in every culture," said forensic psychiatrist Manuel Saint Martin, who said he has tracked about 50 cases. "It seems to be occurring more commonly now in Western, industrialized cultures rather than in the Southeast Asian islands where it was first noticed."

Cho's rampage had the classic signs, said Saint Martin: "It is very likely this was a case of amok. Amok is the end product of mental disorder where you get homicidal-suicidal behavior."

Other examples include a massacre at a Luby's cafeteria in Killeen, Texas, in 1991 and the so-called McDonald's Massacre in San Diego in 1984 — in both cases, a lone gunman violently vented his grievances by killing strangers before killing himself or being killed.

Julio Arboleda-Florez, head of the psychiatry department at Queens University in Canada, said the Virginia Tech case was identical to others he has studied in North America, including that of the University of Texas student who climbed a tower on the Austin campus in 1966 and opened fire on passers-by, killing 13 before he was himself gunned down.

"The pattern starts with a period of brooding, distress, preoccupations and depression," said Arboleda-Florez. "After a period, the guy grabs a weapon and starts a non-provoked outburst of attacks ... (he) just attacks and kills and maims and then commits suicide."