Tuesday January 4 2011
The study did not look at diagnosed depression
“Girls who go through puberty early are more likely to suffer mental health problems in their teenage years,” The Daily Telegraph reported. The newspaper suggested that these problems may be due to “rows with parents and boyfriend troubles”.
The news is based on a study of over 2,000 girls, which found that those who started their periods before 11.5 years old had the highest rates of depressive symptoms at the ages of 13 and 14. It is important to note that only the level of depressive symptoms was assessed, and not whether these symptoms were serious and persistent enough to qualify as clinical depression. The study itself did not report family rows or boyfriend troubles as potential causes.
Future results from this ongoing study will reveal these girls’ progress later in life, including whether girls whose periods started later eventually experienced similar levels of depressive symptoms as those whose periods began earlier. Such research could also look at whether any of the girls develop a diagnosis of depression. Until this information is available, it is difficult to say whether girls whose periods start early need targeted support to prevent depression.
Where did the story come from?
The study was carried out by researchers from the Universities of Bristol and Cambridge and was funded by the Economic and Social Research Council, Medical Research Council, Wellcome Trust and University of Bristol. The study was published in the peer-reviewed British Journal of Psychiatry.
This research was reported in The Times and The Daily Telegraph. The coverage of the study was more extensive in The Times, which provided a balanced report of the research. Importantly, it quoted the researcher as saying, “It was not clear from the study whether early menstruation is associated with persistent adverse effects on emotional development beyond mid-adolescence.”
What kind of research was this?
This research was part of an ongoing cohort study called the Avon Longitudinal Study of Parents and Children (ALSPAC). This study is looking at the effects of a wide range of factors on children’s health and development. The current study assessed whether there is a link between a girl’s age when her periods start and the risk of depressive symptoms during her early teenage years.
A cohort study is the best way to determine whether there is a link between age at onset of menstruation and later depressive symptoms. This is because it follows individuals over time and can establish the age at which menstruation started and the age of onset of any depressive symptoms.
What did the research involve?
The study recruited about 14,000 pregnant women living in the Avon region who gave birth between April 1 1991 and December 31 1992. The babies born to these women were followed up over time using various methods, including postal questionnaires, as part of this ongoing study.
The current study looked at about 2,000 girls from this cohort, for whom information was available on the age at which their periods started (menarche) and depressive symptoms at ages 10.5, 13 and 14 years. The questionnaire provided by the researchers (the Short Mood and Feelings Questionnaire) asked questions about symptoms such as feelings of low self-esteem and self-worth over the past two weeks.
The researchers used statistical models to investigate whether girls who started their periods earlier had higher levels of depressive symptoms. The average age of the girls’ first period was 12.5 years. Girls whose periods started early (before the age of 11.5 years) and girls whose periods started late (at or after the age of 13.5 years) were compared with girls whose periods started between the ages of 11.5 and 13.5 years. Other factors that might influence results were taken into account in the analyses, including absence of a biological father, socioeconomic status of the family and body mass index.
What were the basic results?
The researchers found that, compared to girls whose periods started between the ages of 11.5 and 13.5, girls who had their first period before the age of 11.5 had higher levels of depressive symptoms at the ages of 13 and 14 years.
How did the researchers interpret the results?
The researchers concluded that “early maturing girls are at increased risk of depressive symptoms in adolescence”. They say that these girls “could be targeted by programmes aimed at early intervention and prevention”.
This study used an appropriate design to investigate whether girls whose periods start earlier are at greater risk of depressive symptoms in early adolescence. It found an increase in depressive symptoms at ages 13 and 14 among girls whose periods started early. There are some points to note:
- The study looked at the level of depressive symptoms rather than the risk of a diagnosis of depression. It is not clear whether any of the girls in this study had depressive symptoms that were serious and persistent enough to warrant treatment or a formal diagnosis of depression.
- This study only analysed data for girls up to the age of 14 years. It is not yet possible to say how depressive symptoms might change after the age of 14 in girls with earlier or later menarche. Girls who mature later may eventually experience similar levels of depressive symptoms to those seen in girls who mature earlier.
- A large number of girls from the initial cohort were lost to follow-up and could not be included in this study. The girls who dropped out of the study were more likely to be socioeconomically disadvantaged, and this could potentially affect results. However, the researchers also looked at individual socioeconomic groups within their sample and found that results were similar across these groups. They, therefore, concluded that the loss of individuals from different groups should not have affected their results.
- Although the study took into account some factors that could affect the results, other unmeasured or unknown factors could also have had an effect.
Longer-term follow-up from this ongoing study will determine these girls’ progress as they get older and could determine whether any of them develop a diagnosis of depression. Until this information is available, it is difficult to say whether targeted support for girls whose periods start early might be helpful to prevent them developing depression.