A shortage of generic stimulants to treat ADHD has caused frustrations for children and adults with the disorder over the past few months. There have been scattered reports of patients going a few days without their medicine, or having to call multiple pharmacies to find their drugs in stock. Others are forced to switch to more expensive brand-name versions because the generic supplies are so low.

Others have had to make a frustrating switch back to short-acting versions of the drugs.

Amphetamine mixed salt capsules (generic Adderall) and methylphenidate HCL (generic Ritalin, Methlyn, Concerta, Metadate) were added earlier this month to the U.S. Food and Drug Administration's drug shortage list. The stimulant shortage -- which is expected to be resolved in a month or so -- is being blamed on increased demand along with federal DEA quotas that prevent too much of the controlled substances from reaching the open market at any given time.

One local child psychiatrist said her patients are still receiving medications, which provide short-term relief from the inattention and agitation that can make it difficult for them to focus and perform well in school. However, the shortage combined with insurance restrictions is still causing a problem, said Dr. Carrie Borchardt of Children's Hospitals and Clinics of Minnesota.

The shortage has particularly cut the supply of generic stimulants that come in an extended-release form (which means patients only have to take one pill a day). While brand name extended-release pills are available, many patients can't afford them because their health insurance only covers generic stimulants, Borchardt said. So they have to take the short-acting generics multiple times to get throught the day.

To avoid their ADHD symptoms surging in the middle of the school day, many students have to step out of class to get their stimulant drugs from their school nurses. Not only is the trip disruptive to the school day, but it alerts classmates to the students who have ADHD, Borchardt said.

"Then their classmates all know," she said. "School is hard enough for (these students) the way it is."