Effects of deep brain stimulation of the nucleus accumbens and anterior limb of the internal capsule on heroin addiction: Over five years of long-term follow-up in a prospective open-label pilot study

Deep brain stimulation (DBS) has been suggested to be a safe and effective therapeutic option for drug addiction. Although sustained abstinence is better predicted by at least 5 years of drug-free duration, few studies have followed DBS-treated addicted individuals for more than 5 years. Twenty patients with treatment-resistant heroin addiction were enrolled in this prospective, single-center, open-label pilot study. Patients who received DBS of the nucleus accumbens (NAc) with or without the anterior limb of the internal capsule (ALIC) were followed up for over 5 years, and continuous abstinence, heroin craving (HC), psychometric instrument scores and late positive potential (LPP) amplitudes served as the outcome parameters. Twelve patients maintained sustained abstinence for five years after DBS treatment, and no severe complications or adverse events occurred. A linear mixed-effects model revealed a significant main effect of postsurgical time and relapse status on HC visual analog scale (HC-VAS), SF-36, SCL-90, HAMD, and Y-BOCS scores. Preoperative marital status, HAMD cognitive and SCL-90 psychoticism subscores significantly differed between abstinent and relapsed patients, and persistent abstinence was correlated with moderate acute (VAS 5-8) and delayed (VAS 4-6) psychopsychiatric responses to stimulation. ERP analysis revealed a significant decrease in the drug-pleasant LPP amplitude (400-1000 ms) from baseline to 2-3 years after surgery. The present study suggested that DBS of the NAc/ALIC is effective for reducing heroin craving and preventing relapse in the long term and may reverse motivational attentional bias from drug-related stimuli to pleasant stimuli for heroin-addicted individuals.