Shared Genetic Influences on Negative Emotionality and Major Depression/Conduct Disorder Comorbidity

• Published in: Journal of the American Academy of Child and Adolescent Psychiatry Vol. 50; no. 8; pp. 818 - 827
• Main Authors: Tackett, Jennifer L., Ph.D, Waldman, Irwin D., Ph.D, Van Hulle, Carol A., Ph.D, Lahey, Benjamin B., Ph.D
• Format: Journal Article
• Language: English
• Published: Maryland Heights, MO Elsevier Inc 01.08.2011; Elsevier; Elsevier BV
• Subjects: Adolescence; Adolescent; Adult and adolescent clinical studies; Affective Symptoms - epidemiology; Affective Symptoms - genetics; Behavior Disorders; Biological and medical sciences; Caregivers; Child; Child clinical studies; Comorbidity; conduct disorder; Conduct Disorder - epidemiology; Conduct Disorder - genetics; Conduct Disorder - psychology; Conduct disorders; Depression; Depression (Psychology); Depressive Disorder, Major - epidemiology; Depressive Disorder, Major - genetics; Depressive Disorder, Major - psychology; Depressive personality disorders; Emotional disorders; Emotionality; Environmental Influences; Female; Gender Differences; Genetic factors; Genetic Predisposition to Disease - genetics; Genetics; Geographic Location; Humans; Interviews; major depression; Male; Males; Medical sciences; Mental depression; Models, Genetic; Mood disorders; Multivariate Analysis; negative emotionality; Pediatrics; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Sex Distribution; spectrum hypothesis; Tennessee; Tennessee - epidemiology; Twins; Tennessee; United States > US; comorbidity; conduct disorder; negative emotionality; spectrum hypothesis; major depression; Mood disorder; Affect affectivity; Emotionality; Word; Conduct disorder; Depression; Emotion emotionality; Genetic determinism; Concomitant disease; Language; Genetics; words: major depression; Social behavior disorder
• ISSN: 0890-8567; 1527-5418
• DOI: 10.1016/j.jaac.2011.05.007

Objective To investigate whether genetic contributions to major depressive disorder and conduct disorder comorbidity are shared with genetic influences on negative emotionality. Method: Primary caregivers of 2,022 same- and opposite-sex twin pairs 6 to 18 years of age comprised a population-based sample. Participants were randomly selected across five regions in Tennessee, with stratification by age and geographic location. Face-to-face structured interviews were conducted with the primary caregiver of a representative sample of twins. Results After accounting for genetic influences on negative emotionality, genetic influences on major depressive disorder/conduct disorder comorbidity were nonsignficant, but only in male twins. Specifically, 19% of the variance in the two disorders was accounted for by genetic factors shared with negative emotionality in male twins. Although the full hypothesis could not be tested in female twins, 10% to 11% of the variance in the two disorders was also accounted for by genetic factors shared with negative emotionality. Common shared environmental and nonshared environmental influences were found for major depressive disorder/conduct disorder comorbidity in male and female twins. Conclusions Negative emotionality represents an important dispositional trait that may explain genetic influences on major depressive disorder/conduct disorder comorbidity, at least for boys. Models of major depressive disorder/conduct disorder comorbidity must simultaneously measure common and specific genetic and environmental factors for a full understanding of this phenomenon. Gender differences require specific research attention in dispositional factors and developmental progression.