Whether you have adult attention deficit hyperactivity disorder (ADHD) or are just a busy person on the go, you've probably developed your own strategies for multitasking: paying bills while checking email, preparing for a meeting while cooking dinner, or spending time with your kids while scribbling down to-do lists. And you probably think you're pretty efficient when you multitask, right? Think again.

A growing body of research shows that people who try to manage more than one unrelated task at the same time typically don't perform as well; drivers chatting on cell phones, for instance, take longer to reach their destinations, a 2008 University of Utah study found.

“Thats the myth of multitasking,” says Edward Hallowell, MD, ADHD specialist and author of CrazyBusy: Overstretched, Overbooked, and About to Snap! Strategies for Handling Your Fast-Paced Life. “Its like playing tennis with two balls: Your games not as good as it would be with one ball.”
More about adult ADHD

How to stop?
Strive to give each task your full attention. Dr. Hallowell tells of a lawyer who negotiated an amazing deal. Later, the adversaries couldnt believe theyd agreed to such terms. The savvy lawyers secret? He focused on the deal only, while the other team checked their PDAs.

You can achieve this type of focus if you go linear—do one thing at a time, moving from one task to the next. Try it: Instead of talking on the phone while answering emails and helping your child do homework, go linear; it wont take longer and youll be sharper.