Interoception and alcohol addiction: Vagotomy induces long-lasting suppression of relapse-type behavior.

Drug addictions are chronic mental disorders characterized by compulsive drug seeking and drug use, despite their negative consequences. It is a priority to find therapeutic alternatives to prevent relapse, as there are still no treatments that can ensure abstinence. One of the neural systems implicated in the appearance of the states of discomfort that motivate relapse is the interoceptive system, which oversees our internal body states. However, less attention has been given to the peripheral components of the interoceptive system and their role in addictions. Within these pathways, the vagus nerve represents one of the main visceral afferents of the interoceptive system. We hypothesized that the interruption of visceral afferent pathways would decrease the motivational effects of the drug, thereby either decreasing or preventing drug cravings. To test this idea, we used rats of a high-alcohol-drinking line and measured the effect that vagus nerve resection had on the relapse-like alcohol drinking, expressed as the alcohol deprivation effect, a phenomenon that has been linked to addiction-related events such as alcohol cravings. We found that even though vagotomy completely eliminates the effect of alcohol deprivation, it has no impact on water consumption or animal weight. These results give us valuable information about the relationship between the autonomic nervous system and alcohol use disorders and allow us to propose new clinical research that might have translational options.

A Longitudinal Preliminary Study of Addiction-Like Responses to Food and Alcohol Consumption Among Individuals Undergoing Weight Loss Surgery.

Reductions in addiction-like food behaviors and increases in alcohol intake have been reported after weight loss surgery. However, no studies have tracked these measures in combination and prospectively. In this preliminary study, 27 participants underwent bariatric surgery (Roux-en-Y gastric bypass (RYGB) (n = 10) and sleeve gastrectomy (SG) (n = 6)), dietary weight loss (n = 6), or no treatment (n = 5). Participants were weighed, completed the Yale Food Addiction Scale (YFAS), and reported alcohol intake frequency before intervention and at 4 and 24 months after baseline. At 24 months, only the surgery group showed significant reductions in BMI. Between baseline and 24 months, YFAS scores decreased (p = .006) and alcohol intake increased in the surgery group (p = .005). Significant changes were not observed in the diet or no treatment groups.

Associations between personality changes and nucleus accumbens ablation in opioid addicts.

AIM: It has been reported that nucleus accumbens (NAc) lesions can help to prevent relapse in opioid addicts. This article aimed to investigate associations between personality changes and NAc lesions. METHODS: The surgery group consisted of 78 patients who had received bilateral stereotactic lesions of the NAc to treat opioid addiction. Seventy two non-surgery opioid addicts were appropriately paired with the patients of the surgery group as the non-surgery group. All participants were interviewed in person and received urine tests, naloxone provocative tests and hair tests to determine the prevalence of relapse. Eysenck personality questionnaire (EPQ) and the health survey questionnaire (SF-36) were employed to assess personality and functional health, respectively. RESULTS: In the surgery group, 30 participants relapsed, and the non-relapse rate was 61.5% (48/78). Compared with the Chinese normative data, the neuroticism (N) and psychoticism (P) dimensions of the EPQ in the non-surgery group were significantly higher, whereas the lie (L) dimension was significantly lower. There was no significant difference in all dimensions of the EPQ between the surgery group and the Chinese normative data. The N dimension in the relapse group and the L dimension in the surgery group were significantly lower than those of the non-surgery group. The P dimension in the relapse group was significantly higher than that of the non-relapse group. The extraversion (E) dimension was relatively stable between these groups. CONCLUSION: Although the influence of other factors cannot be excluded, it is apparent that surgically induced NAc lesions are associated with lower P and N dimensions for opioid addicts, and a higher P dimension is associated with a tendency to relapse.