"People in this state tend to behave in ways that are short-sighted. It's a very potent feeling," he said. "What happens in situations like this is that rational trading behavior goes out the window."
The best solution to psychologically weathering an uncertain market, psychological experts say, is to strive to maintain some sense of mental equilibrium -- a feat perhaps better achieved by those who have ridden out financial tempests in the past.
"Most important is what most people call cognitive restructuring," Johnson said. "Some individuals who have been through periods like this before are able to focus on all of the positive aspects of the job. These types of individuals tend to do better in this type of crisis."
Berns agreed that the approach has its merits. "Basically the idea is that you have to engage the conscious, rational part of your brain to make the emotional part shut up."
He said such a strategy might involve pulling out portfolio statements from last year and finding that you aren't poorer than you were a year ago. This, he said, will give a much better idea of your progress than a weekly or daily spot check.
"Don't look at it every day," he said. "Some people are obsessed with checking their portfolios. When you do that, all you're seeing is noise."
Gun-shy investors may do well to adhere to a few simple tips to maintain their mood, as well as their health, Lieberman said. This includes waiting at least 24 hours after a loss before making any new financial decisions, and realizing that money doesn't determine your self-worth.
And for those experiencing full-blown anxiety or mental breakdowns, seeking professional help -- rather than the kind that can be found at the bottom of a bottle -- may be the best course of action.
"One key is not to use alcohol or drugs to try and ride it out," Johnson said. "To use an American phrase, it is better to just roll with the punches."