Women experience more depression during their childbearing years. And twice as many women as men are clinically depressed, according to standardized tests. This gender difference begins in adolescence and is more pronounced among married women aged 25 to 45 with children.
Researchers at ARS' Grand Forks Human Nutrition Research Center in North Dakota wanted to know if this phenomenon is related to marginal iron levels.
About 1 in 5 women of childbearing age has low iron stores, compared to 1 in 60 men, says Janet R. Hunt, a nutritionist and dietitian. So she and psychologist James G. Penland tested the iron status and psychological state of 384 women aged 20 to 45 years.
"Other studies on the question have tended to go both ways," Hunt says. "But there has never been a strong case for a relationship. Our study indicates no relationship between marginal iron status and depression."
The survey volunteers filled out a standard psychological profile and mood checklist and also gave a blood sample. Hunt says the study used the most sensitive tests of iron stores and standardized psychological profiles, unlike some earlier tests.
The researchers found no relationships between mood scores and three signs of iron status in the blood—serum ferritin, serum iron, and hemoglobin. But the study did yield some surprises, says Hunt.
Women with low ferritin levels were less likely to describe themselves as depressed or tired than women with normal ferritin. The researchers believe the finding may be unique to this group of women and not representative of the population in general.
A severe iron deficiency, however, could cause fatigue and depression, Hunt says. Anemia would show up in a simple hemoglobin or hematocrit test. "So women experiencing these symptoms would not need to have their ferritin levels tested as has been suggested in the lay press," says Hunt.
More surprises: Iron stores were not associated with meat consumption or the use of iron supplements. But iron stores were higher in women who used oral contraceptives and lower in women who regularly donate blood.—By Judy McBride, Agricultural Research Service Information Staff.
Janet R. Hunt is at the USDA-ARS Grand Forks Human Nutrition Research Center, P.O. Box 9034, University Station, Grand Forks, ND 58202-9034; phone (701) 795-8328, fax (701) 795-8395.
"Women's Depression Not Linked to Low Iron" was published in the May 1999 issue of Agricultural Research magazine.