Benzodiazepines associated with increased Alzheimer's risk

Benzodiazepines are well known to be deleterious to brain health with more than very short-term use. Research just published in BMJ (British Medical Journal) presents evidence that use of benzodiazepines longer than three months to treat anxiety or insomnia is associated with a substantial increase in the risk of Alzheimer's disease.The authors note urgent public health concerns regarding dementia:

Rising tide of dementia

"Dementia is currently the main cause of dependency in older people and a major public health concern affecting about 36 million people worldwide. Because of population growth and demographic ageing, this number is expected to double every 20 years and to reach 115 million in 2050, resulting in tragic human consequences and social costs. As there are no effective treatments, the search for putative modifying factors remains a priority. Several studies have shown that benzodiazepine use could be one of these. This class of drugs is mainly used to treat anxiety or insomnia. Prevalence of use among elderly patients is consistently high in developed countries and ranges from 7% to 43%. International guidelines recommend short term use, mainly because of withdrawal symptoms that make discontinuation problematic. Although the long term effectiveness of benzodiazepines remains unproved for insomnia and questionable for anxiety, their use is predominantly chronic in older people."

Benzodiazepines and dementia

"While the acute deleterious effects of benzodiazepines on memory and cognition are well documented, the possibility of an increased risk of dementia is still a matter of debate."

So they investigated the relation between the risk of Alzheimer’s disease with exposure to benzodiazepines that started at least five years before, in 1796 subjects who ended up developing Alzheimer's who were matched with 7184 controls and found:

"Benzodiazepine ever use was associated with an increased risk of Alzheimer’s disease (adjusted odds ratio 1.51). No association was found for a cumulative dose <91 prescribed daily doses. The strength of association increased with exposure density 1.32 for 91-180 prescribed daily doses and 1.84 for >180 prescribed daily doses and with the drug half life (1.43) for short acting drugs and 1.70 for long acting ones."

Benzodiazepines duration and discontinuation

A comment in Medscape Family Medicine states:

"The investigators note that although these medications are important treatment options, clinicians should "comply with good practice guidelines" and prescribe benzodiazepines for as short a time as possible. In addition, use should not exceed 3 months."

Note: Benzodiazepines in long term use should never be discontinued abruptly and without the guidance of a clinician due to the likelihood of serious adverse withdrawal effects.The authors conclude:

"Benzodiazepine use is associated with an increased risk of Alzheimer’s disease. The stronger association observed for long term exposures reinforces the suspicion of a possible direct association, even if benzodiazepine use might also be an early marker of a condition associated with an increased risk of dementia. Unwarranted long term use of these drugs should be considered as a public health concern."