Auricular acupuncture for substance use: a randomized controlled trial of effects on anxiety, sleep, drug use and use of addiction treatment services

This randomized controlled trial investigated the efficacy of auricular acupuncture in treating anxiety symptoms, sleep problems, drug use, and health service utilization in adults with substance use disorder and psychiatric comorbidity. The research was conducted at an addiction clinic in Örebro, Sweden, between October 2010 and June 2014. The 280 participants were randomized into three groups: auricular acupuncture following the NADA protocol (15 sessions), auricular acupuncture following an adapted local protocol (10 sessions), and a control group receiving relaxation with music. The NADA protocol used five specific auricular points (Sympathetic, Shen Men, Kidney, Liver, and Lung), considered ideal for patients with addiction problems.

Primary outcomes were anxiety (measured by the Beck Anxiety Inventory - BAI) and insomnia (measured by the Insomnia Severity Index - ISI), assessed at baseline, after 5 weeks, and after 3 months. Results showed that all three groups had significant improvements in anxiety symptoms and sleep problems over time. In the NADA group, the BAI score decreased by 7.2 points; in the local protocol, it decreased by 6.3 points; and in the control group, it decreased by 11.7 points between baseline and the 3-month follow-up. For the ISI, reductions were 2.5, 5.2, and 6.0 points, respectively.

Critically, there were no statistically significant differences between groups in any of the primary or secondary outcomes. Effect sizes were small (η²=0.03 for BAI and η²=0.05 for ISI). Regarding substance use, only about 9-12% of participants reported relapse to alcohol or other drug use at follow-ups, with no significant differences between groups. The study faced an important limitation: a high dropout rate (57% of participants dropped out before the 3-month follow-up).

Participants who remained in the study were older, more often inpatients, and completed more treatment sessions. The clinical implications suggest that auricular acupuncture, as administered in this study, did not prove more effective than simple relaxation for anxiety, sleep, or substance use problems. The authors interpret that the effects observed across all groups may be attributable to nonspecific therapeutic factors, such as the support provided by regular contact with healthcare professionals, or regression-to-the-mean effects. This finding is consistent with previous systematic reviews that failed to find robust evidence for acupuncture in substance use disorder treatment.

The study has important strengths, including the use of a relatively unselected sample of inpatients and outpatients, conferring high external validity, and a design that included an adequate control group to control for nonspecific therapeutic factors.