WASHINGTON (Reuters Health) - Adversaries in the debate over widespread prescribing of Ritalin and other stimulants to children squared off on Capitol Hill Thursday, only to arouse the ire of lawmakers who accused them of serving as fronts for the drug industry and religious groups.

A parade of witnesses came before the House Government Reform Committee to tell lawmakers why an estimated 3 million to 6 million US children are currently on Ritalin and other drugs used to treat attention deficit hyperactivity disorder (ADHD). Committee members voiced concern that doctors are too quick to diagnose the disorder and prescribe strong drugs in children who may not actually have a mental disorder.

Chief among the drug's detractors were three witnesses from the Citizen's Commission on Human Rights, an anti-psychiatry watchdog group. The organization points out that scientists have no reliable way of confirming a child's ADHD diagnosis and that teachers have too much sway in convincing doctors to medicate unruly children.

In addition, parents are rarely informed about the possible side effects of Ritalin and similar drugs like Adderall before agreeing to give the drug, said Bruce Wiseman, the group's US president.

ADHD is now diagnosed in 3% to 5% of all US children, most of them boys, according to the National Institute of Mental Health.

Lawmakers said that federal agencies like the Food and Drug Administration should do more to inform doctors and the public about potential side effects, including heart irregularities, eating disruption, and psychosis.

But Rep. Constance Morella (R-MD) pointed out that the Citizen's Commission for Human Rights (CCHR) was founded in 1969 by the Church of Scientology, a religious group known both for attracting celebrity members and for vehement opposition to all of psychiatry.

Morella read a statement from Jan Eastgate, the organization's international president, which calls psychiatry a "malignant disease" that "threatens society and ultimately mankind."

Wiseman said he agreed with that view, and said that his group maintains an independent tax status from the Church of Scientology.

Morella also challenged Dr. Mary Ann Block, a board member who treats ADHD children with nutritional and anti-allergy interventions instead of drugs. Block accused psychiatrists and other doctors of prescribing ADHD drugs for financial gain.

"You'd probably gain a little bit too if people were scared away from psychiatric drugs," Morella said.

The committee also heard from Children and Adults with Attention Deficit/Hyperactivity Disorder (CHADD), a group that defends the widespread treatment of children and adults diagnosed with the disorder.

The CEO of CHADD, E. Clarke Ross, told the committee that ADHD may be underdiagnosed in US kids and that more doctors should be aware of professional guidelines governing the identification and treatment of the disease.

Ross, whose 11-year-old son Andrew has a severe attention disorder and anxiety, told the committee that drugs have helped his child.

"My son's problems are neither 'lies' nor 'frauds' nor the 'failures of his parents,'" he said in a statement. A few minutes before, committee member Benjamin Gilman (R-NY) told witnesses that federal researchers must do more to uncover possible causes of attention disorders, including poisoning with lead or mercury from vaccines.

Gilman also attacked Ross's group for promoting stimulant drugs on behalf of their makers.

Gilman quoted a Drug Enforcement Administration study concluding that Ritalin maker Ciba-Geigy, now known as Novartis, had given CHAAD over $700,000 in grants over five years in the 1990's. The agency expressed concern in the report that CHAAD and similar groups serve as front organizations for drug makers.

"Here we have a drug company that is influencing a parental group, and that drug company has a strong financial interest," Gilman said.

Psychiatrist David Fassler told lawmakers that drug treatment "can be extremely helpful" in treating ADHD but that "medication alone is rarely the appropriate treatment."

"Medication should only be used as part of a comprehensive treatment plan that will usually include individual therapy, family support and counseling and work with the schools," said Fassler, who heads the American Academy of Child and Adolescent Psychiatry.