Transdiagnostic irritability in youth: a clinical review

Irritability is one of the most frequent concerns in pediatric mental health and a predictor of long-term psychopathology and burden. This article aims to provide a comprehensive review of non-episodic irritability along with evidence-based clinical recommendations for pediatric care professionals.

A narrative review was conducted based on the literature from the last 10 years and additional key studies. Observational studies, randomized controlled trials, systematic reviews, and meta-analyses were considered.

Non-episodic irritability is a transdiagnostic construct associated with several mental disorders. Research on etiological pathways suggests that irritability may involve distinct mechanisms, moderate heritability, and genetic associations with attention-deficit/hyperactivity disorder (ADHD), and depression. Clinical manifestations vary across different developmental stages, and distinguishing pathological from normative irritability may be challenging. Although there is no gold-standard measure, validated instruments are available. Despite recent advances, evidence-based treatment remains limited. Evidence supports psychosocial interventions that integrate parent- and child-focused components, as well as the use of stimulants for patients with comorbid ADHD. Antipsychotics are effective in reducing irritability in children with autism spectrum disorder. However, its use requires caution in non-autistic youth with irritability without a diagnosable disorder or with oppositional defiant disorder due to inconclusive efficacy and potential adverse effects.

Although publications on non-episodic irritability have increased, the evidence remains relatively nascent. Further research is needed to advance the knowledge on underlying mechanisms, enhance clinical recognition, identify effective interventions, and support the development of new treatments, ensuring that irritability is adequately addressed in clinical practice.