The problem of drug shortages in the United States is getting more attention. The Washington Post reported on Monday that doctors, hospitals and federal regulators were struggling to cope with an unprecedented surge in shortages of many commonly used drugs.

Well, now reports are emerging that many parents are having a hard time finding some drugs used to treat attention deficit hyperactivity disorder (ADHD).

The biggest problem appears to be shortages of the drug Adderall XR and its two generic versions. The drugs are made by Shire Pharmaceuticals. According to Shire spokesman Matt Cabrey, the problem is due to “supply and distribution irregularities” that “are due mainly to the restricted amount of active ingredient” used to make the drugs. The availability of the ingredient, an amphetamine, is tightly controlled by Drug Enforcement Administration because it is a potent stimulant prone to abuse.

While spot shortages are being reported around the country, “in general, with few exceptions as reported from various regions of the country, there is sufficient supply”of the drug, Cabrey said. The company expects the problem to be alleviated by the end of May.

Nevertheless, the problem has gotten the attention of Sen. Amy Klobuchar (D-Minn.), who sent a letter to the company last week urging the firm to work to alleviate the shortages.