The researchers say that the data is preliminary but that there is a strong possibility of a causal link.

In research, one lesson every scientist learns fast is “correlation is not causation.”

Two things can happen at the same time, correlation, but that does not mean one caused the other.

In this case, however, there is a sound basis for thinking there is correlation between second-hand smoke and psychological costs serious enough to lead to hospitalization.

This is yet another reason why the anti-smoking efforts of public health officials are important.

My mother used to believe that when she smoked, “I’m not hurting anybody but myself.” Many smokers of her generation believed that because there was no science to prove otherwise.

Smokers who do believe that, but who learn they may be putting family members and friends at risk, could have a powerful incentive to quit.

If you are a smoker or exposed to second-hand smoke, please read this full story carefully.

U. S. News and World Report

“Where there’s secondhand cigarette smoke, there’s emotional fire. As exposure to cigarette fumes increases among nonsmokers, so does their risk of developing serious psychological distress and of being hospitalized for mental ailments, a new study finds. (Emphasis added)

“Cigarette smokers have been shown to have more psychological problems than nonsmokers do, and new evidence suggests that nonsmokers who inhale high levels of secondhand smoke may experience nearly as much psychological distress as smokers, say epidemiologist Mark Hamer of University College London and his colleagues. Overall, these findings support the view, largely based on animal studies, that nicotine administered in large enough doses can induce sadness and other negative moods, the researchers propose in the August Archives of General Psychiatry.

“Our data are preliminary, but there is a strong possibility that the observed association reflects a causal link,” Hamer says.”

Source: U.S. News and World Report/Science News (Magazine for Science and the Public) June 8, 2010

Citation: Archives of General Psychiatry, Publication date, August, 2010.