The study, published today in PLOS ONE, involved Levine's colleagues, Assistant Professor Tatjana Gazibara at the University of Belgrade and PhD student Marija Milic at the University of Pristina. Together, they surveyed more than 2,000 students enrolled at Serbian universities with differing socio-political and economic environments. The researchers found that students who smoked had rates of clinical depression that were two to three times higher than did their non-smoking peers. Specifically, at the University of Pristina, 14% of smokers suffered from depression as opposed to 4% of their non-smoking peers, and at Belgrade University, the numbers were 19% to 11%, respectively.

Further, no matter their economic or socio-political backgrounds, students who smoked also had higher rates of depressive symptoms and lower mental health scores (such as vitality and social functioning) than did non-smoking students. "Our study adds to the growing body of evidence that smoking and depression are closely linked," shared Levine. "While it may be too early to say that smoking causes depression, tobacco does appear to have an adverse effect on our mental health."

In Israel, the timing of the study's publication coincides with a milestone event in the country's war on tobacco. Today, an amendment to Israel's Law on Restriction on Advertising and Marketing of Tobacco and Smoking Products went into effect. It mandates a countrywide ban on store displays of tobacco products, an increase in the size of cigarette box warnings from 30% to 65%, and requires all tobacco and e-cigarette products to be sold in uniform packaging, with no individual logos or company branding.

While these are important steps, in light of the new findings, Levine would like to see policy makers take into account smoking's mental health effects, as well. "I urge universities to advocate for their students' health by creating smoke-free campuses that not only ban smoking on campus, but tobacco advertising, too." Combined with policies that prevent, screen and treat mental health problems, including addiction, these steps would go a long way towards combating the harmful effects that smoking has on our physical and mental states.