RESUMEN
Objective: To explore the reasons and factors associated with new psychoactive substances abuse among patients with access to methadone maintenance treatment (MMT). Methods: A well-developed questionnaire and urine tests were used to collect information about demographic characteristics, condition of MMT and drug abuse, family and social support of MMT clients. A 1∶1 matched case-control study was conducted, and conditional logistic regression model was used to identify factors associated with new psychoactive substances abuse. Results: A total of 212 (106 pairs) clients receiving MMT were recruited, and most of them were males (78.3%, 166/212), married or cohabitant (48.6%, 103/212) and unemployed (63.2%, 134/212). The average age of the clients was (45.1±7.2) years. The main types of abused new psychoactive substances were benzodiazepine (62.3%, 66/106) and methamphetamine (39.6%, 42/106). The proportion of abusing multi new psychoactive substances was 8.5% (9/106). Results from multivariate conditional logistic regression analysis indicated that using opioid drug during the past 6 months of MMT treatment might increase the risk of abusing new psychoactive substances (OR=3.25, 95%CI: 1.35-7.79), benzodiazepine (OR=3.25, 95%CI: 1.11- 9.47) and methamphetamine (OR=13.31, 95%CI: 1.12-158.01). Moreover, MMT for more than9 years reduced the risk of abuse of new psychoactive substances (OR=0.03, 95%CI: 0.01-0.21), benzodiazepine (OR=0.02, 95%CI: 0.00-0.36) and methamphetamine (OR=0.02, 95%CI: 0.00-0.69). Conclusion: Less new psychoactive substances abuse might be associated with longer duration of MMT treatment. And inappropriate support from family and friends might increase the risk of abusing new psychoactive substances in MMT clients, especially in clients who used opioid.