Suicidal behaviors and irritability in children and adolescents: a systematic review of the nature and mechanisms of the association

While many psychiatric disorders are associated with an increased risk for suicidal behaviors (SB) in children and adolescents, a few studies have explored the role of clinical symptoms based on a dimensional approach. Irritability is seen as a marker, a general psychopathology, and a symptom of both externalizing and internalizing disorders. In this review, we are interested in determining whether and how irritability can predict SB in youth. First, we reviewed consistencies and variation in the literature linking irritability to suicidal ideation (SI) and suicide attempt (SA). Second, based on the available models, we proposed specific mechanistic pathways, whereby irritability may modulate the risk for SB. Irritability has been found associated with SB both in cross-sectional and in longitudinal studies. The relation is consistent in different settings (i.e., general population and clinical settings) and across psychiatric disorders. The association is reduced but persists after adjusting for psychiatric disorder, including depression. On one hand, irritability constitutes a risk factor for SI via the onset of internalized disorder. On the other hand, irritable youth may be more prone to attempt suicide when experiencing SI. The measures for irritability were heterogeneous. A limited number of studies were designed to explore the role of mediators and/or moderators. Recognizing irritability in children and adolescents is a key issue with regards to suicide prevention.