Transcranial Ultrasound Stimulation as an Emerging Treatment for Substance use Disorder: Promise and Precaution

Transcranial ultrasound stimulation (TUS) – also referred to as low-intensity transcranial focused ultrasound stimulation (LIFU or tFUS) – is an emerging non-invasive neuromodulation method under investigation for SUD treatment [3] and broader psychiatry applications [4]. Animal and human studies show that TUS can safely modulate subcortical regions with millimetre-scale precision (1–5 mm), including the nucleus accumbens (NAcc) within the ventral striatum which is a central part of the reward network [5,6,7,8].<br/><br/>TUS therefore holds promise for alleviating symptoms associated with dysfunctional reward processing, such as addictive behaviours, compulsivity and anhedonia. This is a step-change compared with established non-invasive methods – rTMS and transcranial direct current stimulation (tCDS) – which are limited to cortical and centimetre-scale brain targets [1, 7]. The unprecedented ability to stimulate deep in the brain, however, brings a new set of scientific and ethical challenges.