Research Highlights: A review of 5 years of health records for more than 130,000 adults with insomnia who had used melatonin for at least a year found they were more likely to be diagnosed with heart failure, require hospitalization for the condition ...
As you seem to know, it is an anticholinergic drug and they have been linked to faster dementia onset. The original study lumped them all together. This study suggests anticholinergic antidepressants and bladder antimuscarinics might be the ones to blame and antihistamines not so much. I am not a doctor but I’ve taken 25mg of benadryl or a melatonin at bedtime for a long time so I’m watching these. I switched to taking melatonin exclusively because of the dementia thing.