My instant reaction to the Cyprus deposit levy was that it could trigger a panic among depositors in the rest of Europe but that it was also perfectly possible there would be no reaction.

FORBES: Cyprus Deposit Levy: No Panic Yet But Scary Long-Term Consequences

"The situation in Italy can be extrapolated to carry larger significance in Europe, but the reality is that the Continent's financial system is much more stable than when regional political events could trigger a panic-induced sell-off, " said Yoshihiro Okumura, general manager at Chibagin Asset Management.

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But the real worry, for investors and European leaders alike, is that a Greek departure could trigger panic elsewhere, with runs on banks in Portugal and Ireland and maybe Italy and Spain.

ECONOMIST: The costs of break-up: After the fall | The

But can the level of fear be adequate to engender such a change of heart while not so powerful as to trigger panic?

ECONOMIST: How much do Greece and the rest of Europe stand to lose?

Secondary factors such as misinterpreting the attack as a heart attack or impending madness, and avoiding situations that might trigger panic attacks interfered with the person's life more than the actual panic attack itself.

BBC: Panic attack gene breakthrough

Disasters such as that currently unfolding in Japan often trigger a rise in scam texts and e-mails intended to fool users into downloading malware or simply to spread panic.

BBC: 'Radiation' text message is fake