Pregnancy not tied to risk of mental illness.

Pregnancy does not raise the risk of developing any of the most prevalent mental disorders, with the notable exception of postpartum depression, according to a report in the Archives of General Psychiatry.

"Pregnancy is traditionally viewed as a stressful period that may provoke mental illness. However, [except for] major depressive disorder among postpartum women, rates of the most prevalent psychiatric disorders are not significantly higher and, in some cases, are even lower in pregnant and postpartum women than in nonpregnant women of childbearing age," said Dr. Oriana Vesga-Lopez of the New York State Psychiatric Institute and her associates.

Pregnant and postpartum women are widely considered to be vulnerable to psychiatric disorders, but no study to date has used methods that permit accurate estimation of the prevalence of a wide range of such disorders among pregnant women in the general U.S. population.

Dr. Vesga-Lopez and her associates used a nationally representative sample of 43,093 adults surveyed in person as part of the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions conducted by professional lay interviewers in the U.S. Census Bureau. This included nearly 15,000 women of childbearing age, of whom 453 were pregnant at the time of the survey, 994 were postpartum, and 13,025 were neither ("nonpregnant").

The 1-year prevalence of psychiatric disorders ranged from 0.4% (psychotic disorders) to 14.6% (substance use disorders) in pregnant and postpartum subjects, compared with 0.3%-19.9% for the same diagnoses in nonpregnant women, the researchers said (Arch. Gen. Psychiatry 2008;65:805-15).

Dr. Vesga-Lopez had no disclosures.

BY MARY ANN MOON

Contributing Writer