Chronic versus episodic irritability in youth: a community-based, longitudinal study of clinical and diagnostic associations.

OBJECTIVE

Irritability is both a normal developmental phenomenon and a common psychiatric symptom in children. In psychiatric nosology, a distinction is made between chronic and episodic irritability. This study examines the validity of this distinction.

METHODS

A sample of 776 youths received Diagnostic and Statistical Manual of Mental Disorders (DSM)-based structured interviews at three time points. Questions regarding episodic and chronic irritability were used to create scales measuring these constructs; associations with age, gender, and diagnosis were examined.

RESULTS

Episodic and chronic irritability differed in their associations with age. The longitudinal stability within irritability type was stronger than between types. In longitudinal analyses, chronic irritability at time 1 (mean age 13.8 +/- 2.6 years) predicted attention deficit/ hyperactivity disorder at time 2 (mean age 16.2 +/- 2.8 years) and major depression at time 3 (mean age 22.1 +/- 2.7 years). Episodic irritability at time 1 predicted simple phobia and mania at time 2.

CONCLUSIONS

Episodic and chronic irritability in adolescents appear to be stable, distinct constructs. Further research is needed to elucidate the longitudinal associations of each with specific psychiatric diagnoses.