09Brain Fog, Mood and Sleep
Real, measurable, mostly transient — and frequently misdiagnosed as depression or early dementia.
Key takeaways
- —SWAN's cognitive substudy demonstrated a measurable but small decline in processing speed and verbal memory during the transition, with recovery in postmenopause.
- —The transition is a window of vulnerability for new and recurrent depression, especially with a prior history or PMDD.
- —Sleep disruption is often multifactorial: VMS awakenings, primary insomnia, restless legs and undiagnosed OSA, which rises sharply after menopause.
- —Oestrogen has evidence for depressive symptoms in the perimenopause but not in established postmenopausal major depression.
- —WHIMS: MHT initiated after 65 increased dementia incidence — prevention is not an indication at any age.
Graded claims
Cognitive performance dips during the transition and recovers postmenopause
Supported in defined populationsSWAN cognitive substudy, longitudinal within-woman design.
The perimenopause is a window of increased depression risk
Supported in defined populationsHarvard Study of Moods and Cycles, SWAN, Penn Ovarian Aging Study.
Transdermal estradiol reduces depressive symptoms in perimenopausal women
Supported in defined populationsMultiple small RCTs including Gordon 2018 prevention trial.
MHT started after age 65 increases dementia risk
Supported in defined populationsWHIMS — combined arm; oestrogen-alone arm directionally similar but non-significant.
MHT prevents Alzheimer's disease
Refuted or actively misleadingNo supporting RCT evidence; not an indication.
Obstructive sleep apnoea prevalence increases after menopause
Supported in defined populationsConsistent cohort data; often missed because presentation differs from men.
Supporting references
- Longitudinal changes in cognition in the menopausal transition (SWAN) — Greendale et al., Neurology 2009 https://pubmed.ncbi.nlm.nih.gov/19487648/
- Efficacy of Transdermal Estradiol and Micronized Progesterone in the Prevention of Depressive Symptoms — Gordon et al., JAMA Psychiatry 2018 https://pubmed.ncbi.nlm.nih.gov/29322164/
- Conjugated Equine Estrogens and Incidence of Probable Dementia (WHIMS) — Shumaker et al., JAMA 2003 https://pubmed.ncbi.nlm.nih.gov/12771112/