Associations between personality changes and nucleus accumbens ablation in opioid addicts

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.

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.

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.

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.