# Light Therapy Alleviates Addiction‐Related Symptoms and Reshapes Habenula and Midbrain Pathways

## TL;DR

Light therapy helps reduce addiction symptoms in internet gaming disorder by improving brain connectivity.

## Contribution

This study shows light therapy can reshape brain pathways and alleviate addiction symptoms in IGD.

## Key findings

- Light therapy reduces addiction severity, gaming duration, craving, and withdrawal symptoms more than placebo.
- Light therapy increases functional connectivity between the habenula and medial orbitofrontal cortex.
- Changes in brain connectivity correlate with reduced withdrawal symptoms and addiction severity.

## Abstract

The treatment of internet gaming disorder (IGD) poses a significant challenge. Light therapy has demonstrated efficacy in preventing cocaine‐driven reinstatement in a rodent model. The potential of light therapy, along with its underlying neural mechanisms, in treating IGD remains largely uninvestigated. A total of 104 participants are included in the RCT and 69 in the fMRI analysis. The intervention involves 14 daily sessions of light therapy, light placebo, or cognitive training. At post‐intervention, light therapy group shows treatment effects comparable to those of cognitive training group, with greater reductions in addiction severity, weekly gaming duration, craving, and withdrawal symptoms than the placebo group. Longitudinal fMRI shows reduced activation in right inferior orbitofrontal cortex (iOFC), left inferior frontal gyrus, and right insula. Using habenula, ventral tegmental area (VTA), and dorsal raphe nuclei (DRN) as seeds, light therapy increases functional connectivity between habenula and medial OFC (mOFC), and VTA and mOFC. These increases are significantly correlated with reductions in withdrawal/craving symptoms. Importantly, changes in withdrawal symptoms mediate the association between habenula‐mOFC functional connectivity and addiction severity. Our findings suggest light therapy is effective in alleviating withdrawal symptoms and ultimately reducing addiction severity by reshaping the habenula‐mOFC functional connectivity in IGD.

This study investigates light therapy for treating Internet Gaming Disorder (IGD). Functional MRI (fMRI) data reveal that light therapy enhances brain connectivity, particularly between the habenula and the medial orbitofrontal cortex (mOFC). These changes are associated with reduced withdrawal symptoms and addiction severity, highlighting the potential of light therapy as a novel therapeutic approach for IGD.