Most people with health insurance in South Carolina could get more mental health coverage under a bill working its way through the state House of Representatives.

But mental health officials argue the bill doesn't go far enough to provide equal coverage for mental and physical illnesses, despite the increased coverage the legislation would require. Others representing businesses claim the coverage would increase premiums for all those with insurance unless the diseases and amount of treatment are restricted.

The bill would require companies with more than 50 employees to provide insurance coverage for specific mental illnesses for up to 45 days of inpatient care and up to 60 outpatient visits a year. About 950,000 South Carolinians would get the increased coverage, according to the state Budget and Control Board.

About one in five adults suffer from a mental disorder each year, said Mike Walsh, executive director of the Mental Health Association of Beaufort and Jasper Counties.

Last week, the House insurance subcommittee approved the measure, which originated in the Senate. The House Labor, Commerce and Industry committee will take up the bill Tuesday.

"This is not parity," Guyla Daley, president of Beaufort County's chapter of the National Alliance for the Mentally Ill, said about the subcommittee-approved bill. "Parity means equal coverage for mental illnesses and physical illnesses. This is not parity."

Both versions of the bill cover specific diseases, including bipolar disorder, major depressive disorder and schizophrenia, but don't cover substance abuse.

Walsh said his group is worried that by compromising on the diseases and the extent of coverage, there will never be true mental health insurance parity.

"I think we cut out a significant portion of what is critical health care," he said.

Julie Horton, a spokeswoman for the S.C. Chamber of Commerce, said the group would support the bill passed by the House subcommittee because it would restrict what insurance companies would be required to cover.

"We're concerned about any kind of mandates that would pass along higher costs to businesses and their employees," Horton said.

David Almeida, executive director of the National Alliance of the Mentally Ill of South Carolina, said a four-year test run of mental health parity for state employees showed the average rate of increase in insurance costs for mental health coverage was less than 1 percent.

"The cost concerns," he said, "are not real."

The legislation would require the state Department of Insurance to calculate how much the mental health coverage would affect insurance costs.

State Sen. Scott Richardson, R-Hilton Head Island, said the measure provides people care without increasing health care costs significantly, as the state test showed.

"We've got to address the fact that people have mental health issues and we shouldn't treat them any differently," said Richardson, a co-sponsor of the Senate version of the bill. "Mental health issues are just as real as any other health issues."

Richardson said he wasn't happy about changing the bill to impose restrictions on how much insurance companies would be required to cover.

The Senate version, passed in mid-March, required companies to provide insurance coverage for specific mental illnesses to the same extent as physical illnesses.

State Rep. Bill Herbkersman, R-Bluffton, said the state would save money by requiring private health insurance companies to cover mental illnesses.

"Once a lot of them get treatment, their quality of life goes up and it's a long-term savings for the state," said Herbkersman, who supported a separate bill in the state House identical to the initial Senate bill.

Some mental health advocates also argue that requiring insurance companies to cover mental illness could save the government money. Daley said many people with mental illnesses turn to government disability as a source of income because disability insurance covers treatment for mental illnesses.

"If people don't have insurance, they can't afford to get this treatment," Daley said. "There's many people on that disability that could enter the work force, but they can't because they don't get health insurance."

Some private insurers cover a portion of mental health care, but the coverage usually is significantly less than physical health care. Almeida said many health insurance companies cap mental health treatment expenditures at $10,000 a year -- a level most seriously mentally ill patients far exceed.

Almeida said the restrictions included in the bill show biases still hold against mental health issues.

"What this says to me is we still have a long way to go with fighting the stigma of mental illness," Almeida said. "If parity were easy, we would have done it a long time ago."