Ever since the release of A Nation at Risk in 1983, schools have become a battleground for opposing views about how best to educate our children. Battle lines have formed around such contentious issues as whether parents should have the option of choosing charter schools rather than traditional public schools; whether teachers should be evaluated on the basis of the performance of their students on standardized tests; and whether adoption of a standard curriculum across the country will raise student performance on those tests.

All of these issues focus attention on schools without considering the lives of the students who attend them. But performing well in school requires a home life that is relatively free of stress, with nurturing parents who can provide the needed support and direction. And as we move down the economic ladder, these resources become ever more scarce.

A conservative estimate suggests that one in every five children live in families without the financial resources to allow their children these luxuries. And the results show up in the schools where children are expected to focus attention on teachers and learning. Unfortunately, students who live in these households are much less able to concentrate on schooling. Instead, they must cope with stressed parents who are too busy making ends meet to provide an environment conducive to academic development.

To increase these children's success, we need to invest in their families' mental health. Our growing understanding of the importance of emotional well-being is spurring interest in the promotion of mental health, rather than just the treatment of disorder.

Stressed parents, especially those in poor households, are more likely to neglect their children or treat them harshly. Research in the United States and the United Kingdom has shown the adverse effects of poverty on children's mental health. At its worst, it can result in maltreatment. Apart from that, poor parents are simply less able to provide the stimulation and mentoring that children need to succeed in school. A single-minded focus on school policies ignores these influences and leads inevitably to frustration with the subpar performance of our most vulnerable youth.

In a study published in 2011, we examined the effects of poverty on school success across individual states in the U.S. as well as across economically developed countries. The striking results were the same in both cases. The higher the poverty rate in a state or country, the weaker the emotional well-being of its adolescents. Furthermore, the worse that well-being, the lower the scores on standardized tests of academic achievement. All of these effects held despite controlling for a wide range of factors that might explain the poverty-school achievement relation, including money spent on schooling and, when available, average intelligence of the population. Consistent with what we know, the United States scored high on poverty and low on academic success when compared with other nations.

The results for the U.S. were informative with regard to the states that performed the best. One of the highest-scoring states was North Dakota. Now, we have no doubt that North Dakota has fine schools and teachers, but we find it hard to believe that North Dakota has better teachers or more effective educational programs than most of the other states in the study. What it does have is a booming economy with very low unemployment.

With the high rates of poverty in the U.S. clearly holding back human capital development, we need to focus on more than educational reforms to enhance our educational status. We also need an agenda that improves the mental health of children so they can take advantage of the schooling we already provide them.

A national mental health strategy will require interventions for children at every age. One of the most successful programs for children, starting at age 1, is the Positive Parenting Program, also known as "Triple P," which was originally developed in Australia. In studies with more than 16,000 children in the United States, Europe and Australia, the program has improved mental health indicators of children as well as parents on a wide scale. In a dramatic recent demonstration in South Carolina, the program significantly reduced cases of hospital admissions for child maltreatment.

Triple P uses a tiered approach that reaches the majority of families using mass media messages. For those families that are having more difficulty raising their children, more intensive programs are made available, many of which can be delivered over the Internet or by phone. A recent demonstration of a similar project in Ireland shows that such programs can be successfully disseminated in poor urban neighborhoods. And the U.K. has tested Triple P and similar programs on a wide scale. Not surprisingly, studies indicate the greatest success among families with the most problematic relations between parents and their children.

Other programs to improve the mental health of our children can be delivered in schools — in some cases, with no more cost than the training of teachers. It is time that we as a nation begin to invest in these efforts so that youth, especially among the poorest families, can realize their maximum potential within their schools. Placing all our hopes on school reform will frustrate us and leave us with less than complete success.

Romer, Ph.D., is associate director of the Annenberg Public Policy Center of the University of Pennsylvania and director of the center's Adolescent Communication Institute.