Evaluation of Short-Term Psychological Functions in Opiate Addicts after Ablating the Nucleus Accumbens via Stereotactic Surgery

Abstract

OBJECTIVE: To investigate the short-term psychological function of opiate addicts who have undergone ablative stereotactic surgery targeting the nucleus accumbens (NAc) for alleviating opiate drug psychological dependence. METHODS: The psychological functional status of 14 opiate addicts was assessed by standardized psychological tests both before and approximately 3 months after stereotactic surgery. Standardized tests included the Wechsler Adult Intelligence Scale-Revised Chinese (WAIS-RC), the Clinical Memory Scale of Chinese (CMS), the Eysenck Personality Questionnaire (EPQ) and the Symptom Checklist 90 (SCL-90). The evaluation of psychological dimensions included intelligence, memory, personality characteristics and mental health symptoms. RESULTS: Compared with the preoperative state, there was no statistically significant difference in full-scale intelligence quotient (IQ) postoperatively, but without Bonferroni correction a significant decline by 13.55% (p < 0.05) was observed in the Digit Symbol-Substitution subtest of WAIS-RC. The memory quotient (MQ) of CMS demonstrated a significant decline of 10.65% (p < 0.05) postoperatively. Concerning the participants' personality characteristics, a significant postoperative increase (p < 0.05) was detected in the Psychoticism (P) trait of EPQ. The mental healthy severity indexes of SCL-90 were decreased postoperatively. After Bonferroni correction, however, there was no statistical difference between pre- and postoperative results on all assessments. CONCLUSIONS: Although the patients' intelligence measures were not changed significantly, their short-term memory and attention appeared to decline postoperatively. In addition, there was a trend towards change in some personality characteristics postoperatively. The postoperative mental health levels of the patients increased, indicating a trend towards improvement. Stereotactic ablation of the NAc in opiate addicts may be associated with short-term negative psychological functions. Advisement regarding the safety of the new surgical modality and recommendations for further investigation are necessary.