Study finds certain antidepressants may increase dementia risk
Anticholinergic drugs are commonly prescribed to patients to manage muscle spasms and other involuntary muscle movements – it works by blocking a neurotransmitter used by the brain to tell any specific group of muscles to contract. But, a UK study has found that long-term use of certain anticholinergic drugs increases dementia risk, thus complicating the use of such drugs.
Researchers from the University of Nottingham, UK, who tracked more than 58,000 people with and 225,000 people without dementia over 20 years, noted that patients who took even one minimally-effective daily dose of an anticholinergic drug for three years had a 50% greater likelihood of being diagnosed with dementia. The chances were stronger in those diagnosed before 80 years old and remained unchanged despite accounting for participants’ age, gender, and alcohol/smoking habits.
Of the 56 anticholinergic drugs used to improve functioning, including antidepressants (doxepin; paroxetine) and Parkinson’s medication (benztropine; orphenadrine), some however, did not correlate to dementia risk such as antiarrhythmics (disopyramide) or skeletal muscle relaxants (methocarbamol).
Even as some of the underlying conditions treated by anticholinergics, like depression, have their own links to dementia, the researchers recommend careful prescription of these drugs and advise doctors to consider alternative treatment options whenever possible, particularly for middle-aged patients.
Additionally, the researchers theorise that up to 10% of dementia diagnoses could be attributed to anticholinergic exposure – thus making it a major risk factor for dementia along with later-life smoking (14%), physical inactivity (6.5%), midlife hypertension (5%), and diabetes (3%).
