Associations Among Hypothalamus-Pituitary-Adrenal Axis Function, Novelty Seeking, and Retention in Methadone Maintenance Therapy for Heroin Dependency

The Association between the Level of Plasma Oxytocin and Craving among Former Heroin Users

BACKGROUND

Animal studies have demonstrated that oxytocin can influence addiction behaviors and might interact with the dopaminergic system, which is a key component of addiction behaviors. However, related evidence from clinical studies is scarce. The aim of our study was to explore the relationship between plasma oxytocin level and heroin craving among patients receiving methadone maintenance treatment, and to ascertain whether this relationship is moderated by novelty-seeking.

METHODS

The study was conducted in a methadone maintenance therapy clinic of a medical center in Taiwan. Seventy-seven patients with heroin addiction were enrolled. Plasma oxytocin was measured using an ELISA kit. Craving was assessed using an established instrument, the Chinese Craving Scale.

RESULTS

A significant negative association was found between the plasma oxytocin level and craving score, which remained robust after controlling the effects of social support and low-density lipoprotein cholesterol. An interaction between oxytocin and novelty-seeking indicated that this relationship was stronger among patients with a lower level of novelty-seeking.

CONCLUSION

This finding may be taken into account in future studies and may provide a basis for the development of potential treatment for addiction. The effect of oxytocin for the treatment of opioid dependence might be modulated by some psychological factors.

Association between Blood Level of Plasma Oxytocin and Novelty Seeking among Methadone-Maintained Heroin Users

BACKGROUND

Oxytocin interacts with the dopaminergic system, which plays a role in addiction behaviors. The association between oxytocin and addiction was confirmed in animal studies. Novelty seeking is one of the predictors and indicators of drug addiction. The aim of the present study was to probe the association between oxytocin and novelty seeking.

METHODS

The study was conducted in a methadone maintenance therapy clinic of a medical center in Taiwan; 77 patients with heroin dependency were enrolled. Plasma oxytocin was measured using an ELISA kit. Novelty seeking was measured using an established instrument (the novelty seeking subscale of the Tridimensional Personality Questionnaire).

RESULTS

A significant negative association (ρ = -0.27, p = 0.02; r = -0.34, p = 0.003) between the blood level of plasma oxytocin and novelty seeking was found. This association was significant after controlling the effects of perceived social support and the dosage of methadone (r = -0.32, p = 0.006).

CONCLUSION

The negative association between oxytocin and novelty seeking may provide insight into future treatments for addiction. © 2015 S. Karger AG, Basel.

The reductions in monetary cost and gains in productivity with methadone maintenance treatment: one year follow-up

While methadone maintenance treatment (MMT) is beneficial for heroin dependence, there is little information regarding the reductions in monetary cost and gains in productivity following MMT. The aim of this study was to evaluate the changes in the monetary cost of heroin addiction and productivity after one year of MMT. Twenty-nine participants from an MMT clinic were included. The monetary cost, productivity, quality of life (QOL) and mental health status were assessed at both baseline and one year follow-up. The average annual total cost was approximately US$26,485 (1.43 GDP per capita in 2010) at baseline, and decreased by 59.3% to US$10,784 (0.58 GDP) at follow-up. The mean number of months of unemployment dropped from 6.03 to 2.79, the mean income increased to exceed the basic salary, but only reached 45.3% of the national average monthly earnings. The participants׳ mental health improved, but their QOL scores did not increase significantly. After one year of MMT, the monetary cost of heroin addiction fell, both the productivity and mental health of the participants׳ improved, but limited gains were seen with regard to their QOL.