The Meaning of Irritability in ADHD: Systematic Review

To investigate the role of irritability in the psychopathology and functioning of children with ADHD. This review was conducted in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA, a protocol that standardizes the collection of evidence, and was registered at the International Prospective Register of Systematic Review - PROSPERO. Of the 3,902 studies returned from the databases, duplicates and studies that met the exclusion criteria were removed, leaving 24 articles in the review. In children with ADHD, higher levels of irritability were strongly associated with more severe ADHD symptoms and a greater presence of psychiatric comorbidities, including depression, anxiety, and mood disorders, such as bipolar disorder. Irritability showed a positive correlation with Oppositional Defiant Disorder and both internalizing and externalizing behaviors. Cognitive functioning was notably affected, with irritability linked to poorer language skills and lower accuracy in emotion recognition. Children with chronic irritability demonstrated poorer inhibitory control, reduced social skills, and an increased tendency to abandon tasks. Furthermore, irritability was associated with faster reaction times but also lower task accuracy, and it was significantly correlated with suicidality. Irritability appears to exacerbate symptoms in patients with ADHD and increase psychiatric comorbidities. It is essential to consider irritability in the assessment and treatment of ADHD to improve mental health outcomes and the overall prognosis for these individuals.