The analysis of data from more than 4 500 parents and their teen children in the United Kingdom also found that the risk of depression was higher among the children of mothers with low levels of education who had depression after giving birth postpartum depression.
The study was published in the journal JAMA Psychiatry.
"The findings have important implications for the nature and timing of interventions aimed at preventing depression in the offspring of depressed mothers," study author Rebecca Pearson, of the University of Bristol, said in a journal news release. "In particular, the findings suggest that treating depression in pregnancy, irrespective of background, may be most effective."
Depression in the late teens is a public-health issue worldwide and identifying early life risk factors would help guide prevention and intervention efforts, the researchers said.
The U.S. National Institute of Mental Health has more about depression and high school students.