Benzodiazepine use and aggressive behaviour

We read with interest the paper on benzodiazepine use and aggressive behaviour (Albrecht et al., 2014). Such problems are common in clinical practice, particularly in emergency departments, but remain poorly understood. Albrecht et al. stressed that personality factors or alcohol use may influence this effect. They mentioned that benzodiazepine prescription was related to increased aggressive behaviour in individuals who were aggressive at baseline. However, the studies investigating this topic included highly specific samples, or failed to statistically control for concurrent substance use, limiting generalizability, and failed to inform about clinical practice.

Some recent studies shed light on this topic. In animals, a study found that ethanol can heighten aggressive behaviour and flunitrazepam further increased this effect (de Almeida et al., 2010). In humans, a study found that in those who tend to endorse antisocial and impulsive externalizing behaviours appeared to be at greater risk for aggression under the acute influence of alcohol (Birkley et al., 2013). A previous study found that subjects with antisocial personality disorders had a greater increase in aggressive responding after alcohol, compared with subjects without antisocial personality disorders (Moeller et al., 1998). High-risk patients also include patients with borderline personality disorders, impulse control disorder, and persistent alcohol problems (Dell’osso and Lader, 2013).

These studies point out that a combination of several factors can potentiate aggressive behaviour in subjects receiving benzodiazepines. In clinical practice, benzodiazepines should be avoided in patients with alcohol intoxication, or alcohol use disorders, and antisocial or borderline personality disorder comorbidities. Alternatively, second-generation antipsychotics could be interesting in such emergency situations.