A varied body of evidence show that smokers combat disturbed sleep during each phase of their torrid affair with cigarettes, reports Van Winkles.

Based both on assessments of smokers’ sleep and objective recordings of their brain activity, it’s clear that nicotine consumption can take a toll on sleep — even before addiction forms. By acting on multiple brain chemical pathways, nicotine influences sleep and mood. But it’s not yet clear whether nicotine itself or short-term (overnight) withdrawal is primarily responsible for all the rocky rest.