A new study has found that children who reach puberty earlier than their peers have emotional and behavioral problems from an early age. The effects of these psychological issues remain throughout the teenage years.

The study was based on data obtained from more than 3,000 children aged between 4 and 11 years who were part of the Longitudinal Study of Australian children. Parents of these children were interviewed about their child's development and his/her puberty transition.  

Researchers found that boys who hit puberty by age 8 or 9 had more behavioral problems and difficulty in getting adjusted to social environment than other boys of the same age.

"There is a heightened risk for behaviour and emotional problems during puberty; and children who reach puberty earlier than their peers have more of these difficulties in adolescence," said Dr. Fiona Mensah, lead researcher of the study.

Girls who reached puberty early had more emotional problems and social adjustment issues. However, girls didn't have behavioral problems. Researchers found that the psychological problems among these children remained even after researchers accounted for other factors.

"We think that the association between early onset puberty and poorer adolescent mental health is due to developmental processes that start well before the onset of puberty and continue into adolescence," said Mensah in a news release.

The new study provides evidence for the life-course hypothesis. According to this hypothesis, the differences in reaching puberty among children may reflect, in part, the differences in genetic and environmental factors that a child was exposed to during early life.

"Understanding what lies behind early puberty may also tell us much about the origins of emotional and behavioural problems of children and adolescents," professor George Patton said.

The study was conducted by the Murdoch Childrens Research Institute and is published in the Journal of Adolescent Health.

Previous research had shown that early menarche in girls is associated with heart diseases, cancer, adult onset of diabetes and depression. It can also affect lung function and result in adult asthma.