discriminating menopausal 'brain fog' from dementia

The menopause transition interacts with sleep disruption, vasomotor symptoms, stress physiology, mood changes, and competing life demands characteristic of midlife, potentially amplifying day-to-day variability in attention and memory processes (1).

Cognitive symptoms - collectively termed ‘brain fog’ are highly prevalent during the perimenopause and menopause transition (2).

‘Brain fog’ has been defined as (2):

• self-reported impairment in one or more cognitive areas (such as memory, attention, organisation, problem solving, word retrieval) in the absence of a significant, objective cognitive decline
  • can fluctuate (for example daily or across a menstrual cycle) and cause mild to significant distress and impact on quality of life
  • does not result in sustained changes in capacity to perform activities of daily living
  • the most common cognitive symptoms are subjective (or self-reported) symptoms such as:
    • losing a train of thought
    • word finding difficulties
    • loss of immediate focus (what was meant to be done)
    • forgetting information
    • distraction
    • misplacement of items
    • difficulties on multitasking
• these symptoms often cause severe patient distress and can be mistaken by patients (and clinicians) for early-onset dementia
  
• differentiating benign, transition-related cognitive fluctuation from neurodegenerative disease is crucial for appropriate reassurance, investigation, and management

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Practical approach
History and assessment of cognitive assessments (2)

• discuss age of onset, duration and nature of the problem (sudden vs insidious; fluctuating vs progressive)
• consider the context (any menstrual changes, HRT use, associated with other menopause symptoms)
• ask about impact: work/functional impact
• check family history of neurodegenerative disease
• ask about alcohol consumption, smoking and any other substance use
• assess and address vascular risk factors
• rule out other medical conditions, nutritional deficiencies, psychiatric conditions and psychosocial factors that could contribute to or exacerbate cognitive symptoms during midlife.
  • consider sleep quality
    • assess sleep (sleep apnoea, disrupted sleep and insomnia) as well as vasomotor symptoms – which can all exacerbate cognitive symptoms directly or indirectly
      • chronic sleep disruption (often driven by nocturnal vasomotor symptoms/night sweats) directly compromises daytime executive function and memory consolidation
  • review medication - concomitant use of sedative-hypnotics, anticholinergics, or polypharmacy affecting central nervous system function
  • suggested blood tests include full blood count, thyroid function, vitamin deficiencies such as B12, folate, vitamin D, HBA1C, liver and kidney function and inflammatory markers

Management overview:

Treat contributing modifiable risk factors

• manage mood, sleep and vasomotor symptoms – consider HRT, psychological therapies (CBT or other talking therapies)
• review medications and consider a test for thyroid disease, B12 deficiency
• diabetes management
• monitor vascular risk factors and treat accordingly
• encourage physical activity, good hydration and stress reduction strategies
  • promote regular aerobic exercise, stress-reduction techniques (mindfulness, yoga), a balanced diet, and cognitive engagement

When to refer

• atypical features such as neurological signs, seizures, rapid progression
• significant and sudden decline, risk to safety
• family history of early onset (under 65) cognitive impairment/dementia
• objective cognitive deficits confirmed on validated screening tools (e.g., GPCOG)
• cognitive symptoms are progressive and/or interfere substantially with work performance, relationships or quality of life

Reference:

1. Gazerani P. Menopause-related brain fog as a midlife window in women's brain aging: toward ecologically valid measurement and digital phenotyping. Front Hum Neurosci. 2026 Apr 21;20:1814092.
2. British Menopause Society (June 2026). Menopausal ‘brain fog’ or dementia? – a practical guide for clinicians.