Timing of Menarche and the Origins of Conduct Disorder
Burt SA, McGue M, DeMarte JA, Krueger RF, Iacono WG
Arch Gen Psychiatry. 2006;63:890-896
Summary
In this study of 708 adolescent female twins in Minnesota, 62% monozygotic, researchers interviewed the girls and their mothers to determine the age of menarche and presence of conduct disorder symptoms according to the Diagnostic and Statistical Manual of Mental Disorders Third Edition Revised (DSM-III-R). The subjects, enrolled in the Minnesota Twin Family Study 3 years previously, had a mean age of 14.8 years and 98% were white. Precocious menarche, present in 20% of girls, was defined as onset at age 11 years or younger. Of monozygotic twin pairs, 28% were discordant for age at menarche; 42% of dizygotic twin pairs were discordant. Girls with precocious menarche were 1.29 times more likely to have 3 or more DSM-III-R conduct disorder symptoms and 1.67 times more likely to have 2 or more symptoms than girls with typical age at menarche.
The researchers were interested in teasing apart environmental and genetic influences on the correlation of early menarche and conduct disorder. Using a variety of statistical models, they found that shared environmental influences account for 2% of the variance in timing of menarche but 95% of the covariance between conduct disorder and timing of menarche. Both shared and nonshared environmental influences appeared strongest in explaining conduct disorder in girls with precocious menarche, whereas genetic influences appeared strongest in explaining conduct disorder in girls with average age at menarche. Furthermore, precocious menarche was associated more with onset of conduct symptoms in adolescence than with onset in childhood.
Viewpoint
Previous research has found a correlation between precocious menarche and conduct disorder in girls.[1] The correlation of early puberty and onset of behavior problems in boys is less robust. Two hypotheses have been advanced to explain the finding in girls: genetic and environmental. Twin studies are a classic method to explore genetic influences on human behavior and mental disorders. The main deficiencies of this study are the brief interval of the evaluation and the ethnic homogeneity of the sample; if undertaken, subsequent evaluations of the cohort would confirm the persistence of conduct disorder and its correlates.
The researchers conclude that early menarche predisposes girls to adolescent-onset conduct disorder mediated more by the girl's environment than by her genes. In contrast, most girls with conduct disorder have an average age at menarche, but for them, genetic influences are more significant. In some cases, their disorder may have early onset, which is commonly observed in a given disease in the presence of greater genetic loading. The clinical significance of the findings is that preventive intervention may be feasible once further research uncovers the social and family conditions that promote conduct problems in girls with precocious puberty.
Abstract (PubMed) URL: https://www.medscape.com/medline/abstract/16894065
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Cite this: Timing of Menarche and the Origins of Conduct Disorder - Medscape - Jan 16, 2007.
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