The study, which followed almost 3,500 children from age four through to 11, found boys with an onset of puberty by eight to nine years of age had greater behavioural difficulties and poorer emotional and social adjustment from early childhood (four to five years of age). This pattern continued through to early adolescence. Girls with early puberty had more difficulties in emotional and social adjustment from early childhood, but not the behavioural problems found in boys.
The research used the Longitudinal Study of Australian children, in which the parents of the children were interviewed at four time points, and asked questions on puberty transition and timing, behaviour difficulties and psychosocial questions on emotional, social and school functioning. The study found that these differences remained even after accounting for other factors that may be linked to early puberty and mental health, including ethnicity, body mass index and family socioeconomic situation.
Lead researcher, Dr Fiona Mensah, says the study provides new evidence of pre-existing and persistent early childhood differences in socio-emotional well being amongst children who experience early puberty.
"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."
"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."
Professor George Patton says the study supports a 'life course' hypothesis, being that differences in pubertal timing and childhood adjustment may at least, in part, be the result of genetic and environmental factors early in life.
"Understanding what lies behind early puberty may also tell us much about the origins of emotional and behavioural problems of children and adolescents."
The study was published in the Journal of Adolescent Health.