Dealing with an addiction of any type in Starfield will negatively impact the player's character via numerous debuffs that may affect health, O2, damage, and defense. Unlike the various medical conditions players will inevitably deal with during their adventures, addiction does not disappear with minor medical air items or a bit of rest. It remains, tugging at the player and reducing their overall effectiveness.
Starfield: How To Cure Addictions
If you have an addiction in Starfield and need it cured, this guide can help.