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What was the new study about?
The study by Carol Coupland, professor of primary care medical statistics at the University of Nottingham, England, and colleagues evaluated anticholinergics, which were prescribed to nearly 285,000 people aged 55 years and over. About 59,000 of them had a diagnosis of dementia. The information came from a database of medical records of patients in more than 1
Researchers examined the medical records of patients diagnosed with dementia and studied the drugs they had been prescribed from 11 years to one year before their diagnosis. They compared their medications during this period with those of people who were not diagnosed with dementia. They recorded which of 56 anticholinergics were prescribed and at what dose and for how long. They considered factors such as body mass index, smoking, alcohol consumption, other illnesses and the use of other medicines.
The study found a 50% increased risk of dementia in people who consumed approximately one strong anticholinergic every day for three years within this ten-year period. The association was stronger for antidepressants, bladder drugs, antipsychotics and epilepsy drugs, it says in the study. For antihistamines, bronchodilators, muscle relaxants or anti-gastric or cardiac arrhythmic drugs, the researchers found no increased risk of dementia.
The relationship between anticholinergics was greater in people diagnosed with dementia before they were 80 and in people with vascular dementia. Compared to people with Alzheimer's disease, the authors reported.
What are the limits of research?
An important limitation of this type of study is that it is an observational study – implying that there is no way to know if the drugs being used played a direct role in causing dementia. It merely shows that the risk of developing dementia seems to be higher in people taking some of these medications.
It is also possible that some disorders, such as depression, could be an early harbinger of a cognitive decline. For example, it is possible that some people who take antidepressants are actually being treated for dementia because of an early symptom. Therefore, it is their depression that is associated with an increased risk of dementia – not the medicine they are taking. Treat it.
What is the end result?
It is possible, but not proven, that some anticholinergics increase the risk of dementia. If you require long-term treatment for any of the relevant conditions, talk to your doctor about other non-cholinergic medicines, such as: Antidepressants such as Celexa and Prozac. In many cases there can be a choice.