BACKGROUND: The influence of genetic factors on major depressive disorder is lower than on other psychiatric disorders. Heritability estimates mainly derive from cross-sectional studies, and knowledge on the longitudinal aetiology of symptoms of anxiety and depression (SxAnxDep) across the lifespan is limited. We aimed to assess phenotypic, genetic and environmental stability in SxAnxDep between ages 3 and 63 years. METHOD: We used a cohort-sequential design combining data from 49 524 twins followed from birth to age ⩾20 years, and from adolescence into adulthood. SxAnxDep were assessed repeatedly with a maximum of eight assessments over a 25-year period. Data were ordered in 30 age groups and analysed with longitudinal genetic models. RESULTS: Over age, there was a significant increase during adolescence in mean scores with sex differences (women>men) emerging. Heritability was high in childhood and decreased to 30-40% during adulthood. This decrease in heritability was due to an increase in environmental variance. Phenotypic stability was moderate in children (correlations across ages ~0.5) and high in adolescents (r = 0.6), young adults (r = 0.7), and adults (r = 0.8). Longitudinal stability was mostly attributable to genetic factors. During childhood and adolescence there was also significant genetic innovation, which was absent in adults. Environmental effects contributed to short-term stability. CONCLUSIONS: The substantial stability in SxAnxDep is mainly due to genetic effects. The importance of environmental effects increases with age and explains the relatively low heritability of depression in adults. The environmental effects are transient, but the contribution to stability increases with age.
BACKGROUND: The influence of genetic factors on major depressive disorder is lower than on other psychiatric disorders. Heritability estimates mainly derive from cross-sectional studies, and knowledge on the longitudinal aetiology of symptoms of anxiety and depression (SxAnxDep) across the lifespan is limited. We aimed to assess phenotypic, genetic and environmental stability in SxAnxDep between ages 3 and 63 years. METHOD: We used a cohort-sequential design combining data from 49 524 twins followed from birth to age ⩾20 years, and from adolescence into adulthood. SxAnxDep were assessed repeatedly with a maximum of eight assessments over a 25-year period. Data were ordered in 30 age groups and analysed with longitudinal genetic models. RESULTS: Over age, there was a significant increase during adolescence in mean scores with sex differences (women>men) emerging. Heritability was high in childhood and decreased to 30-40% during adulthood. This decrease in heritability was due to an increase in environmental variance. Phenotypic stability was moderate in children (correlations across ages ~0.5) and high in adolescents (r = 0.6), young adults (r = 0.7), and adults (r = 0.8). Longitudinal stability was mostly attributable to genetic factors. During childhood and adolescence there was also significant genetic innovation, which was absent in adults. Environmental effects contributed to short-term stability. CONCLUSIONS: The substantial stability in SxAnxDep is mainly due to genetic effects. The importance of environmental effects increases with age and explains the relatively low heritability of depression in adults. The environmental effects are transient, but the contribution to stability increases with age.
Authors: Michel G Nivard; Suzanne H Gage; Jouke J Hottenga; Catharina E M van Beijsterveldt; Abdel Abdellaoui; Meike Bartels; Bart M L Baselmans; Lannie Ligthart; Beate St Pourcain; Dorret I Boomsma; Marcus R Munafò; Christel M Middeldorp Journal: Schizophr Bull Date: 2017-10-21 Impact factor: 9.306
Authors: Michel G Nivard; Christel M Middeldorp; Gitta Lubke; Jouke-Jan Hottenga; Abdel Abdellaoui; Dorret I Boomsma; Conor V Dolan Journal: Eur J Hum Genet Date: 2016-07-20 Impact factor: 4.246
Authors: Adi Stern; Jessica C Agnew-Blais; Andrea Danese; Helen L Fisher; Timothy Matthews; Guilherme V Polanczyk; Jasmin Wertz; Louise Arseneault Journal: J Child Psychol Psychiatry Date: 2020-02-29 Impact factor: 8.982
Authors: Gitta H Lubke; Patrick J Miller; Brad Verhulst; Meike Bartels; Toos van Beijsterveldt; Gonneke Willemsen; Dorret I Boomsma; Christel M Middeldorp Journal: Am J Med Genet B Neuropsychiatr Genet Date: 2015-09-03 Impact factor: 3.568