As I discussed in an earlier blog post this month, the association between behavior and/or personality traits to developing dementia is a growing topic of interest that I am asked to discuss frequently. Depression, in particular, arouses a lot of interest, as many studies have shown an association between depression and poor physical, social and cognitive functioning. The latest study from the Women’s Health Initiative Memory Study (WHIMS) examined whether depressive symptoms in post menopausal women would increase the risk of developing mild cognitive impairment and/or dementia.
The Women’s Health Initiative (WHI) is a multisite population-based study that assessed the risk and benefits of hormone therapy in healthy postmenopausal women. The WHIMS, was designed to examine the effect of post menopausal hormone therapy on cognition and memory in healthy women aged 65 and older at the study baseline. A total of 7,497 community dwelling post-menopausal women were enrolled in WHIMS. They were aged 65y to 79y at enrollment and were free of Mild Cognitive Impairment (MCI) and dementia. Analyses for this study were based on the 6,376 ( 85%) WHIMS women who completed: (1) a six item Center for Epidemiologic Studies Depression Scale (CES-D), (2) a two item National Institute of Mental Health’s Diagnostic Interview Schedule (DIS) and (3) attended at least one follow up visit.
Typical questions asked on the CES-D were whether (1) the participant felt depressed (blue or down), (2) had restless sleep (3) enjoyed life (4) had crying spells (5) felt sad and (6) felt that people disliked the participant. The two questions from DIS asked whether in the past two weeks or more if the participant felt sad, blue or depressed and whether if they had for two or more years feelings of depression/sadness. Other baseline data included demographic information, medical history, lifestyle variables including physical activity and body mass index (BMI). Cognitive testing was measured using the Modified Mini Mental State Examination (3MS) at baseline and yearly after that.
The protocol for assessing MCI and dementia was divided into four phases that included administering to all participants a screening exam for cognition, a more in-depth cognitive battery, and then an assessment by a physician experienced in diagnosis dementia. If a participant was suspected of having dementia, they underwent the typical “work up” for dementia and that included a brain scan and laboratory blood tests. The physician then provided the final diagnosis of the type of dementia.
Of the 6,376 women included in these analyses, 508 met criteria for having depression. Women with depressive disorder were more likely to be African American, widowed, separated or divorced; had lower education, income, and global cognitive function. A total of 216 participants (3.4%) developed MCI , 102 (1.6%) developed dementia of any type and 285 (4.5%) women developed MCI or probable dementia during follow up. Those women who had depressive symptoms at baseline, were found at follow up (mean 5.4 years) to have a greater risk of developing subsequent MCI and incident dementia compared to those who were not depressed. These associations did not change after controlling for lifestyle variables, cardiovascular risk factors, cerebrovascular disease or antidepressant use.
Few population based studies have examined the association of depression to development of MCI and dementia in women. This study is the first to examine these associations in a large group of post menopausal women. Other notable strengths of this study include its large and multiethnic sample size, drawn from diverse communities across the US. These findings suggest that depression may indeed be a risk factor for dementia in women, and that adequate screening and possible intervention may prevent the onset of cognitive decline and dementia.
Here are 3 articles you can refer to for learning about this particular study or the latest research on depression, women and cognitive impairment:
Goveas JS, Espeland MA, Woods NF et al: Depressive Symptoms and Incidence of Mild Cognitive Impairment and Probably Dementia in Elderly Women: The Women’s Health Initiative Memory Study. J Am Geriatr So 59: 57-66, 2011
Thanks for reading.