Trish Luberda makes her living as an education consultant and advocate for people with special needs.

But those credentials have been of little use in a crisis closer to home, as she has tried desperately to get her hands on the medication that two of her daughters, ages 11 and 17, need to manage their attention-deficit/hyperactivity disorder (ADHD).

In recent months, Luberda has made scores of calls to find pharmacies with the medicine in stock. Once she drove more than 40 miles to get prescriptions filled. She has lost income and time from work and borrowed pills from one child to tide over the other, hoping the next refill would come in time.

"It's more frustrating than I can actually articulate," said Luberda, 48, a Berks County resident. "This should not be happening in America."

For months, adults with ADHD and parents of children with the disability have faced a nationwide shortage of common ADHD medications including Adderall and Ritalin and their generics, which help people focus, perform successfully in school and at work, moderate impulses, and even drive safely.

The scarcity has sparked a congressional inquiry.

Relief is unlikely to come soon, say patient advocates. And who is to blame depends on whom you ask.

Most medicines used by people with ADHD contain stimulants that are controlled substances and regulated by the federal Drug Enforcement Administration. The agency's goal is to prevent abuse and misuse of the drugs, which have been used recreationally and as a study aid by people not diagnosed with the disorder.

Each year, the DEA sets manufacturing quotas for the controlled substances in ADHD medications. Factors considered include past quotas, changes in demand, and medical-need estimates, according to the agency.

It also sets limits on how much of the active ingredients can be obtained by each pharmaceutical company.

The Food and Drug Administration says drug companies attribute the shortage of ADHD medications to those active-ingredient quotas and resulting production delays.

Denise Bradley, a spokeswoman for Teva Pharmaceutical Industries Ltd., an Israeli firm with an office in North Wales, that is a maker of Adderall, called the quota system "the catalyst" for the shortage.

Her company does not wish to assign blame, Bradley said, but "we do think that the system needs to be updated to meet the needs of patients while keeping the control that DEA is looking to enforce."

The DEA has suggested manufacturers are at fault. It has increased allocations for 2012 because companies' reserves were being depleted, DEA spokesman Rusty Payne said. The current difficulty is not because the firms could not have produced enough medicine, he said.

"What we don't control is the business decisions of the manufacturers. That is what is getting lost in this whole thing," he said.

Some consumers have noted that generic ADHD drugs first became hard to find, leading to suspicions that companies were trying to inflate sales of their more-expensive brand-name varieties. However, patients and observers say pharmacies are now short on those, too.

Pharmaceutical firms can seek approval to obtain more of the substances, but that takes a while, and the manufacturing process can be months, according to Children and Adults with Attention Deficit Hyperactivity Disorder (CHADD), a national advocacy organization.

The bottom line, said Ruth Hughes, CHADD's chief operating officer, is that people are hurting, and thousands may not get their medication at all.

"The finger-pointing isn't getting us any closer to a solution," Hughes said.

As shortages, first noticed in the spring, have continued, doctors have tried to substitute hard-to-find medications with others, until pharmacies run out of those, too.

But the drugs are not interchangeable. What is effective for one person may not be for another. Some patients have allergies to additives in some forms of the medications. Nearly half of the people who responded to a recent CHADD survey reported trouble getting their prescriptions filled, and some believed that they had lost jobs as a result of not obtaining medicine.

CHADD, the American Academy of Child and Adolescent Psychiatry, and a coalition of six other medical and advocacy associations are trying to get a meeting with the FDA and DEA to find a permanent solution, Hughes said.

"When something goes wrong, there needs to be a mechanism where these agencies get together and resolve it," she said.

The problem has prompted Congress to seek answers. A few weeks ago, four members of the House of Representatives wrote the DEA calling for an explanation of its quota-setting process. Letters also went to Shire Pharmaceuticals Inc. and Novartis Pharmaceuticals Corp., major manufacturers of ADHD drugs, seeking details about their business practices and manufacturing decisions.

The agency and firms are cooperating, a spokeswoman for the House Committee on Energy and Commerce said.

ADHD is no small issue. Estimates place the number of Americans diagnosed with the disorder at more than 10 million. According to the Centers for Disease Control and Prevention, that includes 5.4 million children - 9.5 percent of the nation's 4- to 17-year-olds. Of those, more than 66 percent take medication.

From 2006 through September 2011, the number of dispensed ADHD prescriptions - most of which contained stimulants - increased nearly 39 percent, according to IMS Health Inc., a medical-information firm.

Areas physicians can attest to their patients' frustration in trying to get the medicines they need. It can be a frequent ordeal: Non-mail-order pharmacies are prohibited from dispensing more than a month's worth at a time.

Not getting his or her medicine can significantly affect a person's ability to perform in school and at work, not to mention relationships and family dynamics.

"There's a lot more sibling strife, so there's a lot more parent strife," said Natalie Knochenhauer, 47, who has ADHD, like her four children, and founded the advocacy and support organization ADHD Aware. "Grades fall, and they're getting in trouble because they're not paying attention in class."

Some parents are afraid to let their teenagers drive without the medication, but the youngsters may need the car to get to school and work.

"There are layers and layers," said Knochenhauer, of Doylestown.

Michael Capella, 20, a Burlington County College student from Cherry Hill, said he recently skipped his medication for several days to have some in reserve in case he had trouble filling his next prescription. He never drives without taking his medicine, and he needs it to focus on his studies, including calculus, analytic geometry, and physics, Capella said.

"The government needs to understand that by not allowing the medications to be available, their decision is having a negative impact on people like me who really need it to succeed in life," said Capella, who plans to become an engineer and works at a Whole Foods Market.

Lauren-Beth Harmelin, 29, of Philadelphia, said she had taken ADHD medication since she was 13. She recently halved her dosage to avoid running out and experienced headaches and anxiety.

The shortage has cost her money, too. Her doctor changed her prescription when it became impossible for Harmelin to find her regular medicine, but it took her insurance company two months to authorize it. Harmelin figures she paid more than $1,000 out of pocket.

CHADD officials say they have heard horror stories around the country - a mother who called 100 pharmacies, a person who drove 100 miles one way to get the medicines.

Meanwhile, the FDA and some manufacturers, including Teva, say new supplies of the drugs are weeks away.

"We know we're going to have to ride this out until at least March or April," said CHADD's Hughes, "but we don't want this to ever happen again."

Contact staff writer Rita Giordano at 856-779-3841,, or @ritagiordano on Twitter.