Monday, July 1, 2019

Study Identifies Different Classes of Childhood Irritability


Irritability is known to be a feature of several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD) and disruptive mood dysregulation disorder. A study of irritability in children published today in AJP in Advance suggests there are several forms of irritability, including a “neurodevelopmental/ADHD-like” type with onset in childhood and a “depression/mood” type with onset in adolescence. These findings could have implications for diagnosis and treatment.

Lucy Riglin, Ph.D., of Cardiff University and colleagues assessed data from the Avon Longitudinal Study of Parents and Children (ALSPAC), a long-running, longitudinal study of families in Avon, England, in which children were born between April 1, 1991, and December 31, 1992. This analysis included data from the mothers of 7,924 children, who were asked to assess their children’s irritability (severe temper tantrums, touchy and easily annoyed, and angry and resentful) at ages 7, 10, 13, and 15 using the Development and Well-Being Assessment. Total irritability scores could range from 0 (none) to 6 (high).

The researchers identified five distinct developmental trajectory classes of irritability for these children:
  • Low (81.2%); characterized by irritability scores of less than 1 throughout childhood
  • Decreasing (5.6%); characterized by irritability scores of around 3 at age 7 that gradually went down to less than 1 by age 13
  • Increasing (5.5%); characterized by irritability scores of less than 1 until age 10, then rising to a score of around 4 by age 15
  • Late-childhood limited (5.2%); characterized by irritability scores rising from around 1 to 3 between the ages of 7 to 10, then dropping back below 1 by age 15
  • High-persistent (2.4%); characterized by irritability scores of 4 or more throughout childhood

The decreasing group, high-persistent group, and late-childhood limited group were more likely to be male. In contrast, the increasing trajectory group was about 60% female. The decreasing group, high-persistent group, and late-childhood limited group were also significantly associated with an ADHD diagnosis in childhood. In contrast, the increasing trajectory group was more strongly associated with a diagnosis of depression during adolescence.

“In conclusion, our study identified different developmental trajectories of irritability, including one with characteristics typical of neurodevelopmental/ADHD-like problems—early onset, male preponderance, and clinical and genetic links with ADHD—and one with characteristics typical of depression/mood problems—later onset, female preponderance, and clinical and genetic links with depression,” Riglin and colleagues wrote. “Both groups were associated with risk of adolescent depression, and both were associated with ADHD genetic risk scores. Overall, these findings suggest that the developmental context of irritability may be important in its conceptualization, and this has implications for treatment as well as nosology.”

For related information, see the Psychiatric News article “Irritability in Childhood May Point to Teens At High Risk for Suicide.”

(Image: iStock/Stígur Már Karlsson /Heimsmyndir)