OBJECTIVE: To evaluate the incidence and timing of hot flashes and depressive symptoms during the menopausal transition. We examine whether these 2 symptom processes are operating independently or whether symptoms co-occur. In those women who experience both symptoms we identified which symptom was reported first.DESIGN: Prospective Cohort.MATERIALS AND METHODS: The experience of 170 symptom free women at baseline from the ongoing PENN ovarian aging cohort were evaluated. Reports of hot flashes and depressive symptoms were assessed annually beginning in 1997 using validated questionnaires. The incidence of hot flashes and depression are estimated, and statistical tests of independence between these symptoms was computed using chi-squared methods. Additional comparisons looked at which symptom was reported first and the observed frequencies were compared to expected quantities under the assumption of independence.RESULTS: Women were aged 35-47, average 41.9 (+/-3.4) years, with regular menstrual periods for 3 months enrollment. Reproductive hormones reflected pre-menopausal levels, estradiol average 43.6 (+/-31.9), FSH average 8.0 (+/-4.5). Forty-one percent were African American and 59% Caucasian. Over 10 years these women contributed 1220.6 person-years of follow-up. The incidence of hot flashes was statistically significantly increased in these women compared to the incidence of depression, 62.5% versus 50% respectively, chi-squared test of homogeneity=14.3, p-value=0.0002. Women were more likely to experience both symptoms, whether sequentially or concurrently, than expected if these processes were independent, Chi-square=18.5; df=3; p=0.0007. Seventy women (41.2%) reported experiencing both hot flashes and depressed mood. Depressive symptoms occurred first, prior to reports of hot flashes for 23.5% of women, this was 2.1 times higher than would be expected if these 2 symptoms operated independently. Only 7.7% of women reported hot flashes that proceeded depressive symptoms, this was 31% fewer women than expected under independence, RR=0.69.CONCLUSIONS: Large numbers of women in their late reproductive years report symptoms of hot flashes and depressed mood. Symptoms of depression were more likely to occur first, prior to reports of hot flashes. This pattern is contrary to the theory that hot flashes are a likely cause of depression. Both processes have been associated with changes in reproductive hormones, but these patterns of reporting indicate the potential for different underlying mechanisms. OBJECTIVE: To evaluate the incidence and timing of hot flashes and depressive symptoms during the menopausal transition. We examine whether these 2 symptom processes are operating independently or whether symptoms co-occur. In those women who experience both symptoms we identified which symptom was reported first. DESIGN: Prospective Cohort. MATERIALS AND METHODS: The experience of 170 symptom free women at baseline from the ongoing PENN ovarian aging cohort were evaluated. Reports of hot flashes and depressive symptoms were assessed annually beginning in 1997 using validated questionnaires. The incidence of hot flashes and depression are estimated, and statistical tests of independence between these symptoms was computed using chi-squared methods. Additional comparisons looked at which symptom was reported first and the observed frequencies were compared to expected quantities under the assumption of independence. RESULTS: Women were aged 35-47, average 41.9 (+/-3.4) years, with regular menstrual periods for 3 months enrollment. Reproductive hormones reflected pre-menopausal levels, estradiol average 43.6 (+/-31.9), FSH average 8.0 (+/-4.5). Forty-one percent were African American and 59% Caucasian. Over 10 years these women contributed 1220.6 person-years of follow-up. The incidence of hot flashes was statistically significantly increased in these women compared to the incidence of depression, 62.5% versus 50% respectively, chi-squared test of homogeneity=14.3, p-value=0.0002. Women were more likely to experience both symptoms, whether sequentially or concurrently, than expected if these processes were independent, Chi-square=18.5; df=3; p=0.0007. Seventy women (41.2%) reported experiencing both hot flashes and depressed mood. Depressive symptoms occurred first, prior to reports of hot flashes for 23.5% of women, this was 2.1 times higher than would be expected if these 2 symptoms operated independently. Only 7.7% of women reported hot flashes that proceeded depressive symptoms, this was 31% fewer women than expected under independence, RR=0.69. CONCLUSIONS: Large numbers of women in their late reproductive years report symptoms of hot flashes and depressed mood. Symptoms of depression were more likely to occur first, prior to reports of hot flashes. This pattern is contrary to the theory that hot flashes are a likely cause of depression. Both processes have been associated with changes in reproductive hormones, but these patterns of reporting indicate the potential for different underlying mechanisms.