Brain Stimulation in Addiction

Abstract

Localized stimulation of the human brain to treat neuropsychiatric disorders has been in place for over 20 years. Although these methods have been used to a greater extent for mood and movement disorders, recent work has explored brain stimulation methods as potential treatments for addiction. The rationale behind stimulation therapy in addiction involves reestablishing normal brain function in target regions in an effort to dampen addictive behaviors. In this review, we present the rationale and studies investigating brain stimulation in addiction, including transcranial magnetic stimulation, transcranial direct current stimulation, and deep brain stimulation. Overall, these studies indicate that brain stimulation has an acute effect on craving for drugs and alcohol, but few studies have investigated the effect of brain stimulation on actual drug and alcohol use or relapse. Stimulation therapies may achieve their effect through direct or indirect modulation of brain regions involved in addiction, either acutely or through plastic changes in neuronal transmission. Although these mechanisms are not well understood, further identification of the underlying neurobiology of addiction and rigorous evaluation of brain stimulation methods has the potential for unlocking an effective, long-term treatment of addiction.

Figures

Figure 1

Overlap of brain regions to target in addiction with brain stimulation methods. (a) Human brain regions implicated in addiction. Top. Illustration of the major areas of the brain implicated in addiction based on imaging studies. Perspectives are from (left to right) cortical surface, sagittal, coronal, and horizontal perspectives (inset shows approximate view) Bottom. Approximate distances of implicated brain regions from skin surface above frontal and parietal bones. (b) Methods of brain stimulation. Top. Illustrations depicting methods of brain stimulation used in human from left: repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS) with theoretical range of depolarization and action potential level of stimulation from current delivered. Bottom: Theoretical range of direct stimulation shown in distance from skin surface above frontal and parietal bones. Both tDCS and rTMS can stimulate cortical regions, while can DBS reach deeper subcortical structures.