Teenagers of depressed mothers are more likely to use marijuana, drink and smoke cigarettes - and start at an earlier age - than their peers with healthier mothers, CBS News reported.

These same teens are more likely to act out in other delinquent or violent ways too, a new study published in Pediatrics said.

The results aren't a surprise for researchers, as they expected teens of depressed mothers to be more likely to engage in risky behaviors.

"Those children may be missing both the supervision and support that a parent can offer during an emotional time," said study co-author Ian Colman, an associate professor of epidemiology at the University of Ottawa in Canada. "So we were surprised to see that maternal depression when the child was aged 6 to 10 was actually more strongly associated with those risky health behaviors."

These ages are when peers start to have more influence on children, and parental support and guidance is highly needed.

"It is during this stage that children gain approval from parents and teachers by exhibiting competencies and activities that are valued by society," said Seanna Crosbie, director of program and trauma-informed services at Austin Child Guidance Center. "If children do not receive positive feedback and encouragement from their environment, they may develop a sense of low self-esteem and inferiority."

A depressed parent may not be able to give their children the positive feedback and psychological support they need, leading children to engage in higher-risk behaviors as they mature, according to U.S. News and Health Report.

For the study, Canadian mothers filled out questionnaires about their partners, themselves and their children's social environment. At the age of 10, the children started filling out their own questionnaires regarding risky behaviors.

The 4 percent of kids who had depressed mothers between the ages of 6 and 10 were about twice as likely to start smoking marijuana compared to children of mothers without depression symptoms.

Though the study didn't delve into the fathers' mental health, Crosbie said this is also an important factor in a child's development.