The data also suggest that the antidepressant - bupropion -- helps these women curb their smoking.
"We are encouraged by the findings given that both depression and smoking are highly prevalent in pregnant, substance-dependent patients and are associated with adverse maternal and neonatal outcomes," said Dr. Margaret S. Chisolm, assistant professor of psychiatry at Johns Hopkins University in Baltimore, Maryland.
Her group compared daily cigarette use based on self-reports from 11 women who used bupropion and from 17 women assigned to another antidepressant, citalopram or escitalopram. The analysis also included 28 women who did not receive antidepressant drugs. All of the women were enrolled in a comprehensive drug treatment program that combines a 7-day residential stay with follow-up outpatient treatment.
Chisolm pointed out that up to 90 percent of pregnant women who are dependent on illicit substances continue to smoke cigarettes during pregnancy. Smoking is at least as harmful to the developing fetus as illicit drugs and increases the risk of miscarriage, separation of the placenta from the uterine wall before delivery, low infant birth weight and increased fetal and infant mortality.
Depression also occurs in up to 75 percent of pregnant, substance-dependent patients, she added.
In women who are not pregnant, bupropion is approved for the treatment of smoking cessation and depression. Bupropion is sold under the trade name Wellbutrin when prescribed as an antidepressant and as Zyban when prescribed to help smokers quit.
Bupropion has not been tested in controlled trials for either smoking or depression in pregnant women.
Because bupropion is an effective antidepressant and smoking cessation medication, Chisolm noted. It is also relatively safe for treating depression in pregnant women, making it an ideal candidate for treating both mood disorders and cigarette smoking. Citalopram and escitalopram have no known effect in smoking cessation.
The results of the study showed that women who used bupropion and citalopram or escitalopram all reduced their smoking. However, there was a trend for greater smoking reduction for women in the bupropion group, who reduced their smoking by an average of 6.4 cigarettes per day compared with 0.4 cigarettes per day for the women who received citalopram or escitalopram.
Patients treated with bupropion also rated their mood, on a scale of 0 to 10, as having improved by 1.9 points versus 0.3 points for patients in the escitalopram/citalopram groups.
Chisolm said that plans are underway for a prospective, randomly assigned controlled pilot trial examining smoking outcomes for bupropion and another antidepressant, sertraline (Zoloft), in depressed pregnant women smokers who are addicted to illicit substances, after which her group will seek funding for a larger trial of the same design.
If bupropion is found to be more effective for smoking cessation than sertraline, the investigators plan to repeat the trials in non-depressed pregnant women.