Endocannabinoid signaling in the lateral habenula regulates opioid addiction

Opioid addiction is a significant health, economic, and social burden worldwide. Negative emotional states, such as stress and depression, often accompany opioid addiction and drive relapse. New developments in neurological research revealed two critical players in opioid addiction: the lateral habenula and the endocannabinoid system. Studies show that these brain structures modulate drug addiction by interacting with the mesolimbic reward system and modulating negative emotional states. However, there remain gaps in knowledge on how the endocannabinoid system works in tandem with the lateral habenula, especially about opioid addiction. This chapter will provide an overview of the endocannabinoid system and lateral habenula, their physiological functions, and their regulatory roles in addiction and negative emotional states. Lastly, this chapter will conclude by elaborating on potential explanations for some of the observed phenomena and provide suggestions to direct future research.