SAN FRANCISCO — Hot flashes may not necessarily be a cause of depressive symptoms, according to a study that followed women in the menopausal transition for 10 years.
“We were interested in whether these symptoms were more likely to occur concurrently and which was more likely to come first among women in this transition period,” Mary D. Sammel, Sc.D., the study's lead author, said in an interview. The leading hypothesis is that hot flashes cause sleep problems, which lead to depressive symptoms in menopausal women, continued Dr. Sammel of the Center for Clinical Epidemiology and Biostatistics of the University of Pennsylvania, Philadelphia.
The study evaluated 170 women aged 35–47 who were enrolled in the ongoing Penn Ovarian Aging Study. Previous studies of this cohort had looked at these two symptom processes separately; the current study analyzed these symptoms together, she said at the annual meeting of the American Society for Reproductive Medicine.
At baseline, the women had no hot flashes or depressive symptoms, had had regular periods for the previous 3 months, and had premenopausal reproductive hormone levels. Women were then assessed annually via questionnaire. About half were white, and the rest were African American. Over the 10-year period, more than 60% of the women reported experiencing hot flashes and 50% reported depressive symptoms. About 41% reported that their hot flashes and depressive symptoms started at the same time.
Of the women who reported having both depressive symptoms and hot flashes, nearly 24% experienced depressive symptoms before they had hot flashes, which was a twofold higher rate than would be expected if the two processes were independent, based on statistical probability estimates. Only 8% of the women reported experiencing hot flashes before the development of depressive symptoms, which was less often than would be expected, based on the statistical probability they would occur in this pattern, Dr. Sammel said.
“Both processes have been associated with changes in reproductive hormones, but these patterns of reporting indicate the potential for different underlying mechanisms,” she and her coauthors concluded.
Previous studies of these women in the Penn Ovarian Aging Study cohort—which also includes women who already had menopausal symptoms when they were enrolled—have shown that the prevalence of depressive symptoms increases at the earliest stages of the menopausal transition, when women are experiencing small changes in reproductive hormones. This is followed by a decline in depressive symptoms in later stages of the menopausal transition, she said.
These findings suggest “it is the fluctuating hormones, earlier in the transition, which are more likely to influence depressive stages, and not the dramatic changes in estradiol and FSH, exhibited later in the transition,” Dr. Sammel noted.