"Our data are consistent with other emerging evidence to suggest a causal role of nicotine exposure in mental health." --- Dr. Mark Hamer
Secondhand tobacco smoke exposure can cause deathly illness, we all know. But there is even worse news now. The most terrifying perhaps of all.
A new study, from a prestigious university, shows that nicotine exposure causes long-term psychological distress--- and the risk of future psychiatric hospitalization!
Too grim, too weird, to be true?
The effects were suffered by otherwise healthy adults, with no previous symptoms of mental illness. They were all subjected to second-hand smoke over a period of 6 years.
Smokers and non-smokers (with high exposure to secondhand smoke) were hospitalized for depression, schizophrenia, delirium, and other severe psychiatric conditions.
The August print issue of Archives of General Psychiatry reports the findings of this astonishing study, by Mark Hamer, Ph.D., and his University College London colleagues.
The research team studied 5,560 non-smoking adults (average age 49.8) and 2,595 smokers (average age 44.8) with no history of mental illness. The subjects had all participated in the Scottish Health Survey in 1998 or 2003.
The subjects were followed through the years by the research team. Admissions to psychiatric hospitals were tracked, as well as mental illness progressions.
Dr Hamer said, "To our knowledge, this is the first study to demonstrate a prospective association between objectively assessed secondhand smoke exposure and mental health in a representative sample of a general population."
How was nicotine exposure scientifically connected to their mental illness? Tests were made for saliva levels of cotinine. When nicotine is broken down by the body, continine is formed. The researchers used it as a reliable biochemical marker of nicotine exposure.
Coincidence? No way. The research leaves no clinical doubt.
Non-smokers (with cotinine levels between 0.70 and 15 micrograms per liter) all suffered increased psychological distress. Their control group (those who had no detectable cotinine) were not hospitalized, and reported themselves mentally healthy.
"A growing body of literature has demonstrated the harmful physical health effects of secondhand smoke exposure," say the researchers. "Given the highly prevalent exposure to secondhand smoke -- in the United States, an estimated 60 percent of American non-smokers had biological evidence of exposure to secondhand smoke -- even a low level of risk may have a major public health impact."