Diagnosis: On the Bipolar Seesaw

In bipolar disorder, the highs aren't always so high. A study of bipolar kids aged 7-17 found that 10 percent experienced only irritability in their manic phases—the same percentage with upswings that were pure giddiness. A majority of the kids showed both elation and irritability.

You could miss a case of bipolar disorder if you're expecting to see states of euphoria, says lead researcher Jeffrey Hunt of Brown University.

How is manic irritability different from regular grumpiness? "The average kid who is frustrated by a parent will usually get back on track within the hour," Hunt explains. Kids who have bipolar disorder show a more exaggerated response, and it goes on much longer. "Irritability, we know from studies, is the symptom that causes families the most burden."

Tame The Beast

Expert advice for dealing with irritable children

• Stay calm: Set an example by keeping cool. Irritable behavior occurs "when the world is demanding skills that the kid does not have," says Ross Greene, author of The Explosive Child. It's not personal.
• Don't aim for a quick fix: Authoritarian directives ("Just sit down and be quiet") don't teach the child any new skills. Neither does ignoring their bad behavior.
• Empathize: Simply saying you understand helps soothe. "'You can't get what you want and I know that makes you angry' is different from 'Snap out of it,'" early-childhood expert Joan Luby points out.
• Verbalize: Encourage kids to talk about their feelings. "You're teaching them how to use language to calm themselves," Greene says.