RALEIGH - The state Senate voted overwhelmingly Tuesday to require employers that offer health insurance to have plans that treat mental illnesses as they do physical ailments.

The Senate voted 36-12 after a lengthy debate about the cost to small businesses and the value of timely treatment for mental illnesses.

The bill now goes back to the House, where members will either agree with the Senate version or decide to negotiate to resolve substantial differences between it and the version that House members approved in May.

Rep. Martha Alexander, a Charlotte Democrat who jump-started the issue in the House, said she liked the Senate version.

"I think it's a great day for North Carolina," she said. "I think it's a really good bill."

But Alexander said she wanted to read it thoroughly before deciding whether to recommend her House colleagues go along with it.

Both the House and Senate versions contain the same basic idea: Insurance companies would treat serious depression and other major mental illnesses the same as they do heart disease and other physical ailments. Co-pays, lifetime limits and other coverage details would be the same.

Currently, few private insurance policies for North Carolina workers cover mental illnesses for more than short periods, and they often impose a lifetime cap that can be reached with just one hospitalization. Supporters say that expanding private insurance coverage would help working people and their families receive proper treatment.

The Senate voted to limit fully equal coverage to nine mental illnesses: bipolar disorder, major depressive disorder, obsessive-compulsive disorder, paranoid and other psychotic disorder, schizoaffective disorder, schizophrenia, post-traumatic stress disorder, anorexia nervosa and bulimia. For other illnesses, policies could impose limits of 30 visits to the doctor and 30 days in the hospital per year.

The House voted to cover all mental illnesses but exempted companies with 25 employees or fewer. Neither plan would cover drug and alcohol treatment.

North Carolina is in the minority of states that do not have such a requirement for insurance.

Some senators argued that they shouldn't start now because the costs would be too high for small businesses and push them to drop their health insurance coverage.

"This is just another burden on small business," said Sen. Robert Pittenger, a Charlotte Republican. "How much more can we put on them?"

Studies of similar laws in other states have found that expanded mental health coverage does not increase costs substantially.

The health insurance plan for state employees includes comparable coverage for physical and mental illnesses. The mental health coverage has not led to increased costs, said Sen. Martin Nesbitt, an Asheviile Democrat.

Workers with untreated depression can end up seeking remedies for physical ailments while never getting to the source of their problems, Nesbitt said.

"We have reached the point in this state and on this planet where if we don't deal with mental illness, it's going to be the end of all of us," he said.