Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA.
Center for Clinical and Translational Research, Virginia Commonwealth University, Richmond, VA, USA.
J Child Psychol Psychiatry. 2019 Sep;60(9):1032-1041. doi: 10.1111/jcpp.13062. Epub 2019 Apr 17.
Little is known about genetic and environmental influences on the components of disruptive mood dysregulation disorder (DMDD), tonic irritability (i.e., irritable mood) and phasic irritability (i.e., temper outbursts). This study examined prevalence, stability, and heritability of tonic irritability, phasic irritability, and a DMDD proxy (pDMDD) based on DSM-5 criteria.
pDMDD was derived using data from clinical interviews of parents and their twins (N = 1,431 twin pairs), ages 8-17, participating in Waves 1 and 2 of the Virginia Twin Study of Adolescent Behavioral Development. Biometrical modeling was used to compare a common pathway model (CPM) and an independent pathway model (IPM), and heritability estimates were obtained for pDMDD using the symptoms of irritable mood (tonic irritability; DMDD Criterion D), intense temper outbursts (phasic irritability; DMDD Criterion A), and frequent temper outbursts (phasic irritability; DMDD Criterion C).
Lifetime prevalence of pDMDD was 7.46%. The stability of DMDD symptoms and the pDMDD phenotype across approximately one year were moderate (.30-.69). A CPM was a better fit to the data than an IPM. Phasic irritability loaded strongly onto the pDMDD latent factor (.89-.96) whereas tonic irritability did not (.28). Genetic influences accounted for approximately 59% of the variance in the latent pDMDD phenotype, with the remaining 41% of the variance due to unique environmental effects. The heritability of tonic irritability (54%) was slightly lower than that of frequent and intense temper (components of phasic irritability; 61% and 63%, respectively).
Compared to tonic irritability, phasic irritability appears to be slightly more stable and heritable, as well as a stronger indicator of the latent factor. Furthermore, environmental experiences appear to play a substantial role in the development of irritability and DMDD, and researchers should seek to elucidate these mechanisms in future work.
关于破坏情绪失调障碍（DMDD）的组成部分——紧张性易激惹（即易激惹情绪）和阶段性易激惹（即情绪爆发）的遗传和环境影响知之甚少。本研究根据 DSM-5 标准，考察了紧张性易激惹、阶段性易激惹和 DMDD 替代指标（pDMDD）的患病率、稳定性和遗传性。
pDMDD 是根据参与弗吉尼亚青少年行为发展双胞胎研究 1 和 2 波的父母及其双胞胎（N=1431 对双胞胎）的临床访谈数据得出的。采用生物测量模型比较共同途径模型（CPM）和独立途径模型（IPM），并使用易激惹情绪（紧张性易激惹；DMDD 标准 D）、强烈的情绪爆发（阶段性易激惹；DMDD 标准 A）和频繁的情绪爆发（阶段性易激惹；DMDD 标准 C）的症状来获得 pDMDD 的遗传力估计值。
终生 pDMDD 的患病率为 7.46%。DMDD 症状和 pDMDD 表型在大约一年的时间内具有中等稳定性（.30-.69）。CPM 比 IPM 更适合数据。阶段性易激惹强烈加载到 pDMDD 潜在因子上（.89-.96），而紧张性易激惹则没有（.28）。遗传因素约占潜在 pDMDD 表型变异的 59%，其余 41%的变异归因于独特的环境效应。紧张性易激惹的遗传性（54%）略低于频繁和强烈的情绪爆发（阶段性易激惹的组成部分；分别为 61%和 63%）。
与紧张性易激惹相比，阶段性易激惹似乎更稳定、遗传性更强，也是潜在因素的一个更强指标。此外，环境体验似乎在易激惹和 DMDD 的发展中起着重要作用，研究人员应在未来的工作中寻求阐明这些机制。
