Just what does it take to make someone snap?

What were they thinking?

Lisa Nowak. Isaiah Washington. Michael Richards. Ryan O'Neal. Mel Gibson. Problem is, whether stalking a romantic rival, assaulting a family member or blurting out bigoted rants (sometimes more than once), they weren't thinking.

They were probably in an altered state, say Flo Conway and Jim Siegelman, authors of "Snapping: America's Epidemic of Sudden Personality Change." The communication researchers define snapping as a sudden, drastic alteration of personality — but say the snap may actually be a long time in coming.

Clues in the past

New York physician Nicholas Bartha appeared to snap when he blew up his Manhattan townhouse last summer — while he was inside — rather than lose it in a divorce. What about the local woman accused of blinding a social-service worker with a knife in a downtown Seattle clinic? Or the Ballard elementary school principal accused of exposing himself to a woman in a car?

We, voyeuristic onlookers, ask ourselves why an astronaut, respected actors, a physician, a principal, would risk their professional reputations and families with such aberrant behavior. After all, who wants their police mug shot to end up on the Internet?

"When people act out of character, they have gone into an altered or dissociative state," says Conway. "They have lost touch with the world they function in. When people go into an altered state, they're not saying 'Oh, yeah, I'm going to risk my family, my job.' "

"There may be tiny changes [over time] that we don't see," adds Siegelman.

Peter Olsson, assistant professor of psychiatry at Dartmouth Medical School, agrees. "It is very common after a person gets wide publicity in the wake of an unusual or violent act that friends, neighbors, colleagues and relatives say things that would make it sound like the action was out of character," Olsson said. "For various reasons, these people might be overprotective, or not be aware of the complex inner conflicts, struggles or impulses that were going on. [They] only observed the external social behaviors of the person."

"Anybody who wants to understand what happened to her [Nowak] needs to go back and look at her past," Siegelman says of the astronaut charged with the attempted murder of a woman she perceived to be a rival for the affection of another astronaut.

Talking it out

According to Siegelman and Conway's theory, snapping is not a psychiatric disorder, it is a communication problem. And any kind of closed situation that isolates people and limits communication and contact — preparing for a NASA mission, for example, or any other high-pressure work situation — contributes to the possibility of snapping.

The only way to prevent snapping, Conway and Siegelman say, is through communication. They cite studies that show Vietnam veterans coped better when they got together and talked. Other studies show that people with post-traumatic stress disorder cope better if they have been through tough times before.

The people Conway and Siegelman write about are not the ones involved in violent episodes like the 18-year old gunman who opened fire at a Salt Lake City mall Monday, killing five people.

The power of resiliency

If mental health is a spectrum, that young man, and the Gary Ridgways, Ted Bundys, Kyle Huffs and the Columbine shooters of the world are at one end, and the rest of us, capable of stress-caused snapping, are at the other.

Ironically, the most vulnerable people may be those with little experience coping with serious problems, people Siegelman describes as having lived a charmed life.

Resilient people tend to view difficulties in life as expected, and to confront and learn from disappointments. They nurture connections in their lives, especially to other people. They also communicate effectively and have empathy. And perhaps most importantly, resilient people know when they need help, and they get it.

It could be you

Conway and Siegelman call snapping a disorder of experience, occurring in otherwise healthy people.

"It is not traditionally a mental disorder, but a disorder caused by intense and stressful life experiences," Siegelman says.

"These can come about suddenly or cumulatively over time ['snapping in slow motion']."

"The smarter the people, the greater the success, the more stress," adds Conway. "The more that is asked of us, the more vulnerable we are. It's possible there is a psychiatric disorder that hasn't surfaced before. But by and large, people who act out are doing it because of emotional stresses that build and build and collide."

And if there is no one to talk to, no way to get emotions out, we might find ourselves ready to snap.

"We're all vulnerable," Conway says. "It can happen to anybody."

Rebecca Morris has been a broadcast and print journalist for 33 years. She teaches journalism at Bellevue Community College.