Bidirectional relationships of irritability with ADHD, depression, GAD, and PTSD in three independent samples of Chinese children and adolescents.

Irritability is a transdiagnostic factor that commonly co-occurs with ADHD, depression, GAD, and PTSD in children and adolescents. However, the bidirectional relationships between these conditions remain understudied. Exploring these relationships could offer valuable insights into the shared and distinct mechanisms underlying children and adolescent psychopathology. Data were from three large samples of Chinese children and adolescents. Sample 1 included 1,360 7th- and 8th-grade students (52.90% male; mean age = 12.77 ± 0.67 years) from Nanchang, Jiangxi Province, with a one-year follow-up. Sample 2 consisted of 1,326 7th- and 10th-grade students (51.30% male; mean age = 13.84 ± 1.49 years) from Chenzhou, Hunan, followed up after 11 months. Sample 3 comprised 5,637 4rd- to 9th-grade students (54.30% male; mean age = 11.50 ± 1.42 years) from Hengyang Hunan, and Jinxian Jiangxi, assessed annually across three waves. Cross-lagged models were used to examine bidirectional associations. Irritability showed a certain degree of stability, that is similar to those of PTSD, depression, GAD, and ADHD. There were bidirectional relationships between irritability, on the one hand, and PTSD, depression, GAD, ADHD, on the other hand in pairwise analyses, regardless of survey durations and measure tools of irritability. When irritability, as well as, other clinical symptoms were modeled simultaneously, longitudinal associations differed across samples, survey durations, and measures. The findings imply general but not specifical longitudinal associations of irritability with emotional and behavioral problems in children and adolescents. Irritability is a relatively stable construct that can indicate the risks of emotional and behavioral problems.