Serotonin2A receptor binding potential in people with aggressive and violent behaviour.

OBJECTIVE Indexes of brain serotonin2A (5-HT2A) density have never been investigated in a sample of humans with violent aggressive behaviour unbiased by medication use or current axis I psychiatric disorders. The objective of this study was to investigate prefrontal cortex 5-HT2A binding potential (BPND), an index of 5-HT2A density, in an unbiased sample of people with violent aggressive behaviour. METHODS We used [18F] setoperone positron emission tomography to measure 5-HT2A BPND in the dorsolateral prefrontal cortex (primarily sampling Brodmann area 9) in 16 participants with violent aggressive behaviour and 16 healthy control participants. RESULTS In people with violent aggressive behaviours, the slope of 5-HT2A BPND decline in the dorsolateral prefrontal cortex is 44% less than in healthy control participants (analysis of variance group by age interaction, p = 0.004). Prefrontal cortex 5-HT2A BPND was significantly lower in participants with more severe impulsivity and aggression (multiple linear regression with age and Barratt Impulsivity Scale [BIS] as predictor variables and regional 5-HT2A BPND as dependent variable; effect of BIS, dorsolateral prefrontal cortex: F1,13 = 7.95, p = 0.014). CONCLUSION Lower prefrontal 5-HT2A BPND is related to violent aggression. Lower 5-HT2A BPND occurs at a younger age, when violent behaviour is more frequent, and is more prominent when impulsivity and aggression are more severe.