RedTracker| Researchers at University College of London have quantified secondhand smoke as a tritter in mental-health problems. Reviewing the records of 8,155 men and women in Scotland, researchers documented a 50% greater risk of psychological distress in nonsmokers with the highest levels of nicotine residue in their blood.
Previous data have suggested a link between smoking and mood disorders. Nicotine exposure in animals is known to trigger depressive symptoms, stress, anxiety and a dampening of feelings of reward and satisfaction. The new findings extend these findings to to nonsmokers who passively inhale cigarette smoke, and while the study does not establish that the exposure directly causes changes in mood, it does suggest a strong association. via TIME