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Causes of dementia
Medical expert of the article
Last reviewed: 04.07.2025
The incidence of dementia varies from 30.5/1000 per year in men to 48.2/1000 per year in women (Bachman, 1992). In Sweden, among people aged 85–88 years, the incidence reaches 90.1/1000 per year (61.3/1000 in men and 102.7/1000 in women). The incidence of Alzheimer's disease is 36.3/1000 per year, vascular dementia is 39.0/1000 per year, and other forms of dementia are 9.1/1000 per year.
The most common cause of dementia in the United States is Alzheimer's disease, followed by vascular dementia and dementia with Leigh bodies. Dementia can also be caused by other diseases: Parkinson's disease, HIV encephalopathy, Pick's disease and other frontotemporal dementias, progressive supranuclear palsy, Cretzfeldt-Jakob disease, Hallervorden-Spatz disease, neurosyphilis, toxic brain damage (e.g., alcoholic dementia). Cognitive impairment is also possible in such mental illnesses as schizophrenia, bipolar disorder, depression, delirium. It is important to differentiate these conditions because they have different prognosis and treatment.
The main causes of dementia are:
- Alzheimer's disease
- Pick's disease
- Diffuse Lewy Body Disease
- Parkinson's disease
- Huntington's disease
- Progressive supranuclear palsy
- Multiple system atrophies
- Fahr disease
- Wilson-Konovalov disease
- "Thalamic" dementia
- Multi-infarct dementia
- Binswanger's disease
- Normal pressure hydrocephalus
- Alcoholism
- Encephalopathy due to exogenous intoxication (carbon monoxide, lead, mercury, manganese, drugs)
- Schizophrenia
- Traumatic brain injury (post-traumatic encephalopathy, subdural hematoma, boxer's dementia)
- Brain tumors (meningiomas, gliomas, metastases, carcinomatous meningitis), subdural hematoma
- Occlusive hydrocephalus
- Metabolic disorders (diseases of the thyroid, parathyroid, adrenal and pituitary glands; renal or hepatic failure, etc.)
- Infection-associated encephalopathies (syphilis, postencephalitic dementia, Whipple disease, AIDS, Creutzfeldt-Jakob disease, subacute sclerosing panencephalitis, progressive leukoencephalopathy)
- Meningitis and encephalitis of any etiology
- Multiple sclerosis
- Leukodystrophies
- Nutritional encephalopathies (vitamin deficiency, folate deficiency, pellagra, pernicious anemia, persistent vomiting during pregnancy)
- Hypoxic encephalopathy (including chronic pulmonary failure, paroxysmal cardiac arrhythmias)
- Iatrogenic (anticholinergics, hypotensives, psychotropics, anticonvulsants, mixed)
- Pseudodementia (depression).
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