Everyone knows that too little sleep changes the way we behave.

Medical science has recently discovered that serious behavioral problems may arise when the quality of sleep is poor.

Here are some lessons physicians have learned:

• "An assessment of sleep patterns and possible sleep problems should be part of the evaluation of every child presenting with behavioral and/or academic problems, especially Attention Deficit/Hyperactivity Disorder (ADHD)."

• "Mood problems in children with sleep disturbances are virtually universal."

• In one study, 44% of children having their tonsils and adenoids removed had disruptive behavior, chiefly oppositional defiant behavior. None of the children in a control group (having a hernia repair) had such behavior.

• "Children at high risk for SDB, in comparison with remaining children, were two to three times more likely to be bullies, constant fighters, sassy to adults, destructive, quarrelsome, disobedient, and cruel."