FRIDAY, May 26, 2006 (HealthDay News) -- Adding to the growing evidence that mental illness in childhood can lead to problems later in life, a new Finnish study suggests that depressed kids are more likely to grow up to become smokers.
Researchers who tracked male children over a 10-year period report that those who had symptoms of depression at age 8 were 20 percent more likely than others to smoke at age 18. The depressed boys were also 40 percent more likely to become heavy smokers.
The study is apparently the first to find a link between childhood depression and adult smoking in a large sample of people, the researchers said. The findings were presented Thursday at the American Psychiatric Association's annual meeting, in Toronto.
The researchers studied over 2,300 boys born in 1981. The boys, their parents and their teachers were surveyed in 1989 about their behavior. In 1999, the boys -- then 18 -- completed more surveys when they were called for mandatory military service in Finland.
In addition to their findings about the depression, the researchers discovered that boys with emotional problems at age 8 were actually 10 percent less likely to smoke.
Why would emotional problems make kids less likely to grow up to be adult smokers? Study lead author Dr. Solja Niemela, a psychiatrist at Turku University, speculated that substance abuse may be a "social phenomenon," and those who are shy and withdrawn may be less likely to experiment with cigarettes.
The opposite seemed to be true of boys who showed signs of hyperactivity: They were 20 to 30 percent more likely to smoke regularly than other boys. The findings are similar to those from a Duke University study released last year that found children with signs of attention-deficit/hyperactivity disorder were more likely to smoke as young adults.
Dr. David W. Goodman, assistant professor at Johns Hopkins University School of Medicine and director of the Adult Attention Deficit Disorder Center of Maryland, called the study findings "exciting."
"We want to identify childhood conditions that leave the child at risk for developing subsequent damaging behavior," Goodman said. And while it's easy to assume that specific mental-health problems might lead to later substance abuse, it's important to confirm it, he added.
The next step is determining whether proper treatment pays off, he said. "Do we reduce the risk of getting into cigarettes, alcohol and drugs?"
Why might depressed people find solace in smoking? Nicotine can reduce anxiety and improve cognition a bit, Goodman said, potentially reducing symptoms of depression. In other words, smoking can be a case of self-medicating, he said.
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