The National Institute of Mental Health, which funded the study, believes that the findings are important in the U.S. because nearly 50 percent of children experience the divorce of their parents. This is the first scientific demonstration of long-term positive effects of programs for children of divorce. The findings also point to the importance of parenting after divorce as a factor with an impact on children's long-term adjustment.

"This study sends an important message," Sandler said. "What we did was teach healthy parenting under difficult circumstances."

"That the program had lasting effects on a wide variety of outcomes is remarkable and speaks to the importance of effective parenting in promoting positive developmental outcomes," added Wolchik.

The current study is a six-year follow-up of previous research done by the same team. For the original study the researchers worked with 240 divorced families (children and custodial mothers), with children ages 9 to 12 years.

The researchers divided the families into three programs -- a self-study literature program, where participants were given books and a self-study program; a program for custodial mothers, where the mother attended an 11-week parenting skills class that focused on listening and communication skills, consistent discipline and other key parenting skills; and a combined program for mothers and children, which included the parenting class and a coping skills class for the children.

Six months after the study the researchers found that children whose mothers attended the class had fewer behavioral problems than those in the self-study program.

For the newly published study, the researchers contacted the same families (90 percent of the original families participated in the follow-up) after six years to assess outcome for the adolescents. Six years after participating in the programs, the majority of the adolescents were still functioning well. The classes were most beneficial for those adolescents who had high levels of behavior problems in childhood and who were most likely to develop more serious problems later in life.

The adolescents in the combined program were 36 percent less likely to have diagnosed mental disorder and reported fewer sexual partners than those who had been in the self-study program. The adolescents whose mothers had attended the class had fewer mental health problems and fewer instances of drug, marijuana and alcohol use than teens that had been in the self-study program. The results for the mother program and the combined mother and child program were not significantly different.

The researchers are now planning a larger project to examine if the class can be effectively delivered to families through community agencies. If successful, this project will raise public policy issues of how society can deliver such effective mental-health prevention programs in the community.