School officials around the U.S. are searching for the best way to offer mental health services in an underfunded system.

"We have (schools) screening for all kinds of rare infectious diseases, and then we don't screen for common behavioral disorders that are costly to the individual, the family and society," said Mike Dennis, of Chestnut Health Systems. He teaches clinicians in 49 states how to assess and treat patients with and substance abuse.

The U.S. Surgeon General reports that 10 percent of children and adolescents suffer from serious emotional and mental disorders that significantly affect their daily lives.

A decade ago, recommended universal screenings for students, but it's still not required. An Associated Press review of policies around the nation shows screenings vary widely. There's no consistency on whether the schools screen, at what age they screen and what they screen for.

The federal government does not keep track of school mental health screening, so it's all but impossible to say how many schools offer it. The offerings vary from intensive services to virtually none at all.

"No state is providing high-end services in all of their schools," said Sharon Stephan, co-director of the Center for School Mental Health, a national organization that provides training for schools and .

Mental health issues typically start during adolescence, but many people are not diagnosed until later in life when they don't have access to services because they don't have health insurance or their insurance doesn't cover it.

However, offering mental health screening in schools can raise other complex issues. Some warn that mass screenings will over-diagnose students and stigmatize them with a life-long label.

Some say mass screenings could uncover that schools lack resources to treat.

"Once we screen and assess and discover the need, I think it's our responsibility to have the resources in place to service every one of those needs that are uncovered," said Denise Wheatley-Rowe, of Behavioral Health System Baltimore.

The organization developed a system that has gained national recognition using a team of school officials and community mental health experts to target students most in need. The program helps nearly 7,000 children a year.

The team identifies children who may need help based on factors like whether they have a parent in prison or who struggles with . It also scans data for those struggling academically and behaviorally, including those with high truancy or suspension rates, and then offers individual counseling or family therapy based on the student's need.