Joanne M. Meyer

TL;DR: Compared DSM-III-R antisocial personality disorder symptoms before vs after the age of 15 years within a sample of twins, characteristics of the shared or family environment that promote antisocial behavior during childhood and early adolescence also promote later antissocial behavior, but to a much lesser extent.

TL;DR: The prevalence rates and patterns of findings from this study of twins are consistent with those of other epidemiological studies, supporting previous findings of few differences in rates of psychiatric disorder between twins and singletons.

TL;DR: The fact that different genetic loci were identified in this and in the European-American samples, lends credence to the notion that these genetic differences together with differences in environmental exposures may contribute to the reported differences in disease prevalence, severity, comorbidity, and course that has been observed in different racial groups in the United States and elsewhere.

TL;DR: The Genetics Initiative of the National Institute of Mental Health (NIMH) was a multisite study that created a national repository of DNA from families informative for genetic linkage studies of schizophrenia, bipolar disorder, and Alzheimer's disease, presenting the results for the European-American sample.

TL;DR: Bivariate model fitting showed that the covariation between hyperactivity and oppositional/conduct problems in both younger and older boys and girls is almost entirely attributable to genetic factors.