Interoception and Substance use: A systematic review and meta-analysis

Introduction: Interoception, the sense of the physiological state of the body, is being investigated as a mechanism involved in substance use disorders (SUDs) and has been linked to reward related and cognitive-affective processes, that are disrupted in SUDs. Methods: This systematic review and meta-analysis investigated interoception during acute substance intoxication and in the context of long-term substance use (i.e., continuous and problematic use). Medline, Psych-Info, Scopus and Web of Science were searched. Studies assessing interoceptive accuracy, sensibility, magnitude and/or meta-cognitive awareness with behavioural or self-report measures in healthy adults during acute substance intoxication compared to placebo, or in adults meeting SUD criteria compared to healthy controls were included. Results: Twenty-seven studies met the inclusion criteria, with 8 studies on intoxication and 19 studies on long-term substance use. Firstly, no significant differences were detected in interoception during substance intoxication vs. placebo. Secondly, SUD participants displayed lower interoceptive accuracy compared to healthy controls (g = -0.7, 95%CI –0.88 to –0.52; p < .001). No significant differences were detected for interoceptive sensibility or magnitude. Significant correlations were observed between SUD-related processes with interoceptive accuracy and sensibility. Conclusion: Our results suggest that substance intoxication does not induce changes in interoception. In the context of long-term use, individuals meeting criteria for a SUD exhibit deficits in interoceptive accuracy. Relationships between interoceptive accuracy and SUD related processes suggest avenues through which these deficits may contribute to SUDs. Future research should explore dimensions (e.g., meta-cognitive awareness) and substances (e.g., cannabis) neglected thus far, and further explore interoception-focused treatment approaches.