Study: Smoking May Cause Depression
By LINDSEY TANNER
AP Medical Writer
CHICAGO (AP) - A new study suggests smoking may be a cause of depression in teen-agers, contradicting the current thinking that says depressed people may smoke to feel better.
The study found that teens who smoked were about four times more likely to develop highly depressed symptoms during a year's time.
The researchers speculated that nicotine or other smoking byproducts may have a depressive effect on the central nervous system.
The study adds to a growing body of conflicting research on links between tobacco and the mind.
``The thing that bolsters the idea is that there is evidence that anti-depressant drugs are helpful in treating nicotine addiction,'' said Dr. Elizabeth Goodman, an adolescent-medicine specialist at Children's Hospital Medical Center of Cincinnati who led the study.
The study appears in the October issue of Pediatrics, the monthly journal of the American Academy of Pediatrics.
Other researchers have linked teen smoking with suicide, and smoking with depression in adults, but they disagree over whether tobacco use is a cause or merely a result of a depressed state.
Most people think that those who tend to be depressed ``self-medicate by smoking. This is probably not the case,'' said Naomi Breslau, director of research at Henry Ford Health Systems in Detroit.
Breslau's own research also has suggested tobacco may somehow contribute to depression. She said that while the new findings do not prove smoking is a cause, they strongly support that theory.
``They find absolutely no evidence that depressive symptoms per se increase the risk for smoking,'' she said. ``They do find very clear evidence in the other direction.''
She added: ``It's just one more adverse effect of smoking on health.''
The study relied not on doctors' diagnoses but on teen-agers' reports of having symptoms suggestive of depression.
The study analyzed data from teens questioned in 1995 and 1996 in a national study on adolescent health. It included 8,704 teens who were not initially depressed and 6,947 teens who were not initially smokers.
Evidence suggesting depression was a cause rather than a result of smoking evaporated when the researchers took into account other factors that may have prompted the teens to start smoking, such as friends' use of tobacco and poor grades.
Current smokers included those who smoked as little as one cigarette in the previous month and those who smoked a pack a day or more. The researchers did not examine whether teens who smoked the most were the most likely to develop depression, but some of their other findings suggest that may have been the case.
After a year's time, 4.8 percent of the nonsmokers had developed depressed symptoms compared with 12 percent of those who initially smoked at least a pack a day.
Linda Pederson, an epidemiologist at the Centers for Disease Control and Prevention's office on smoking and health, said the study was well-done, larger and more nationally representative than previous research that reached similar conclusions.
This Link is to the text the full study in October edition of Pediatrics. Right now the link is so busy that you'll probably not be able to get through. Tomorrow it should be easier. Please note that many medical journals make the text of their current articles available on-line for a limited time and then remove them. Zep