Smoking cessation treatments often fall short, especially for women, but bright light therapy (BLT) shows promise as a non-invasive approach to combat nicotine addiction. Light was shown to suppress activation in the prefrontal cortex (PFC), a key addiction-related region, with a stronger effect in males. This may lead to sexually divergent impacts on nicotine dependence, potentially stemming from differences in dopamine (DA) regulation by the ventral tegmental area (VTA), influenced by estrogen and light. Combining behavioral and neuroimaging studies, we will test the hypotheses that: (1) light exposure would reduce nicotine dependence and restore brain connectivity by suppressing PFC activation; (2) these effects would be stronger in men; and (3) light-evoked VTA modulation, serving as a proxy for DA release in the PFC, would differ between sexes. Participants will undergo an 8-week randomized con-trolled trial of BLT vs. dim light, while monitoring smoking habits, cravings, and nicotine dependence. Resting-state and light-evoked fMRI scans will be collected at baseline and post-treatment to assess changes in network connectivity and VTA activation. Discovering BLT’s potential as a sex-dependent, cost-effective treatment for nicotine addiction could significantly impact not only nicotine addiction but also inform future treatments for other addictions and their mechanisms.