"We've waited a long time for this," said Vilsack, a Democrat.

With some limitations, the new mental health parity law will require insurers to provide coverage for mental illness that is comparable to coverage for physical ailments.

The law covers a category of "biological" mental illnesses that includes schizophrenia and major depression, along with bipolar, schizo-affective, obsessive-compulsive, pervasive development and autistic disorders.

Not covered are eating disorders and substance abuse.

The insurance requirement will apply to group policies provided to companies with more than 50 employees; public employees; and small businesses that currently have mental health coverage.

"I feel like now we have an equal basis with physical disabilities," said Gano Whetstone, a tutor in the Des Moines schools who has a schizo-affective disorder.

Whetstone and other advocates of the legislation crowded into Lt. Gov. Sally Pederson's office at the Capitol to witness the signing of House File 420.

"Today is one more step in making progress to provide health care access for people with mental illness," said Pederson.

"It's incredibly important that we end the discrimination that we've seen for so many years against mental illness," she said.

Iowa joins 46 other states that have adopted some type of mental health parity law.

Mental health advocates say they'll continue to work for an Iowa law that is more comprehensive.