Deep brain stimulation of the nucleus accumbens for severe self-injurious behaviour in children: long-term outcomes from a first-in-human pilot trial.

Children with severe self-injurious behaviour (SIB) are at risk of permanent injury and lack effective treatment options. Neuromodulation of the nucleus accumbens (NAc), a key node in reward and behavioural regulation circuits, may directly modulate the drivers of SIB. We report long-term outcomes from a first-in-human, single-centre trial of deep brain stimulation (DBS) targeting the NAc in children and adolescents with profound autism and treatment-refractory SIB (NCT03982888). Six participants (ages 7-14 years; mean 11.7) underwent bilateral implantation and were followed prospectively for at least 24 months (mean 32.5 months, range 25.8-56.0). One serious adverse event occurred: a device-related infection requiring hardware explantation, followed by relapse to baseline levels of self-injury. Subsequent re-implantation in this participant yielded rapid improvement in SIB, providing single-subject, causal withdrawal-rechallenge evidence of treatment-specific benefit. Across the cohort, NAc-DBS produced sustained reductions in SIB frequency and severity, repetitive and obsessive-compulsive behaviours, and clinically meaningful improvements in quality of life. The durability of these effects over multi-year follow-up suggests that circuit-targeted neuromodulation may modify the developmental course of severe behavioural pathology. These findings provide the first long-term evidence that modulation of reward circuitry can durably alter maladaptive behaviour in childhood neurodevelopmental disorders.