Using a Developmental Approach to Investigate Behavioral, Neurodevelopmental, and Depressive Irritability Types

Area of Science:

• Child and Adolescent Psychiatry
• Developmental Psychology
• Behavioral Genetics

Background:

• Irritability is a heterogeneous symptom common in youth clinical services.
• Diagnostic manuals (ICD-11, DSM-5-TR) conceptualize severe irritability differently, as behavioral or depressive.
• Irritability is prevalent in and genetically linked to neurodevelopmental conditions, but its unitary nature is debated.

Purpose of the Study:

• To investigate distinct behavioral, neurodevelopmental, and depressive irritability types.
• To differentiate these types based on developmental course, sex-preponderance, and clinical, genetic, and environmental factors.

Main Methods:

• Utilized data from the Avon Longitudinal Study of Parents and Children (N=10,113).
• Conducted sex-stratified latent profile analysis of irritability across 5 time points (ages ~7-25).
• Examined associations with clinical, genetic, and environmental covariates.

Main Results:

• Identified 5 common irritability profiles (low, child-limited, child/adolescent-limited moderate/high, high-stable) and 2 sex-specific profiles (female adolescent-onset, male fluctuating).
• The male high-stable profile linked to attention-deficit/hyperactivity disorder, autism traits, and genetic liability.
• The female adolescent-onset profile associated with depression, genetic liability, and stressful life events.

Conclusions:

• Irritability exhibits developmental heterogeneity.
• While often transdiagnostic, specific irritability profiles may align with neurodevelopmental or depressive conditions.
• Findings suggest potential implications for psychiatric classification and targeted interventions.