Resting-state brain function and its modulation by intranasal oxytocin in antisocial personality disorder with and without psychopathy

Behavioural, structural, and functional neuroimaging differences exist between individuals with antisocial personality disorder with (ASPD + P) or without psychopathy (ASPD-P). However, the aetiological mechanisms underpinning such differences remain unclear, hindering treatment development. Intranasal oxytocin (OT) has shown modulatory effects on social brain function in healthy and antisocial populations. We investigated the effects of OT on resting-state brain function in individuals with violent offending histories with ASPD+/-P using arterial spin labelling to measure regional cerebral blood flow (rCBF). A double-blind, placebo-controlled, crossover design was employed with males with ASPD (ASPD + P: N = 17, ASPD-P: N = 14) and healthy male non-offenders (N = 22). Both ASPD subtypes exhibited reduced rCBF in frontotemporal regions compared to non-offenders. Individuals with ASPD + P showed significantly greater rCBF increases in posterior default mode network regions compared to individuals with ASPD-P. OT administration selectively decreased rCBF in the left basal ganglia of the ASPD-P group, an effect not observed in ASPD + P or non-offender groups. These findings highlight functional brain differences between individuals with ASPD + P and ASPD-P at rest and demonstrate oxytocin's differential impact on resting-state measures. Further understanding of the origins of these neurobiological differences could inform targeted therapeutic strategies for individuals with ASPD with and without psychopathy.