What's next for interoception and addiction?

Interoception is the perception of internal stimuli and is tightly coupled to the development of aberrant motivation to consume pharmacological reinforcers characteristic of addiction. We review the current theoretical basis of the role of interoception in addiction, candidate neurobiological mechanisms underlying interoception of drugs, and the place of interoception in the broader theoretical understanding of addiction. Broadly, interoceptive drug stimuli acquire control over appetitive behaviour by functioning as conditioned stimuli, discriminative stimuli, and occasion setters and these processes may involve activation of the insula and modulation of mesolimbic dopamine neurons. Notably, the interoceptive stimulus characteristics and reinforcing characteristics of drugs are distinct in their independence on sensitization and tolerance. Directions for future work on the role of interoception in addiction are discussed.