Decreased interoceptive awareness in patients with substance use disorders

Introduction: The current study was prepared based on the assumption that awareness of the interoceptive processes may be disturbed in addicted individuals, Methods: The participants in the study included 84 abstinent male inpatients who were addicted to alcohol (n = 33), heroin (n = 29), or synthetic cannabinoids (n = 22) according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), and 35 healthy male volunteers. Interoceptive awareness (IA) was measured using the heartbeat perception (HBP) task. Addiction severity was assessed using the addiction profile index (API). Alexithymia was assessed using the Toronto alexithymia scale (TAS-20). Results: Patients addicted to alcohol, heroin, or synthetic cannabinoids had similar IA, and their HBP scores were significantly lower than those of healthy control subjects. There was a significant negative correlation between HBP scores and TAS-20 subscores, thus indicating difficulties in identifying feelings. HBP scores were not significantly correlated with API scores. API scores were significantly correlated with total alexithymia scores and subscores, thus indicating difficulties in identifying and describing feelings. Discussion: As our main finding, a decrease in IA in addicted patients in comparison to healthy controls may provide support for the hypothesis that awareness of the interoceptive processes may be disturbed in addiction.