Diazepam damages the brain permanently

Tranquilizers and Dementia Risk

Bordeaux (France) - Psychotropic drugs from the group of tranquilizers are used to treat anxiety and sleep disorders. Known side effects include temporary impairment of memory and other cognitive functions. A large French-Canadian long-term study has now confirmed the fear that such drugs, if taken for a long time, could also cause permanent brain damage and increase the risk of Alzheimer's disease. Even if a cause-and-effect relationship has not yet been proven, these tranquilizers should only be used for as short a time as possible in patients of all ages, the researchers write in the British Medical Journal. The benzodiazepines include active ingredients such as diazepam (Valium), diclazepam, alprazolam or lorazepam.

“Benzodiazepines are undoubtedly important tools to treat anxiety disorders and temporary insomnia; but the therapy shouldn't last longer than three months, ”warn Sophie Billioti de Gage from the Université de Bordeaux and her colleagues. Based on their results, they consider it likely that these psychotropic drugs could damage brain cells over time in such a way that cognitive brain performance deteriorates faster with age. At the moment, however, an alternative explanation cannot be completely ruled out: Alzheimer's dementia in its early stages could have been the cause of anxiety and sleep disorders in the subjects who were therefore treated with benzodiazepines.

The study collected data from 1,796 people over 66 years old with Alzheimer's disease who had been in a long-term Canadian study for at least six years. 7,184 healthy persons, appropriately selected according to age and gender, served as controls. Those who had been treated with a benzodiazepine for at least three months prior to being diagnosed with dementia were 43 to 51 percent higher risk of developing Alzheimer's than the others. This relationship was stronger the longer the drug was taken and the longer the half-life, i.e. the duration of action, of the respective agent. Cardiovascular diseases, depression, anxiety disorders and insomnia were taken into account in the statistical analysis as possible additional influencing factors.

The authors write that it has already been well researched that benzodiazepines impair memory performance. So far, however, there has been no explanation as to the mechanism by which this treatment could lead to dementia. In order to clarify this question, experiments with animals or cell cultures are necessary. But even now, doctors should carefully weigh the benefits and risks before using benzodiazepines and only prescribe such drugs for a short period - and this recommendation applies not only to old, but also to younger patients.

In an accompanying comment, Kristine Yaffe of the University of California at San Francisco and her co-authors call for better documentation of side effects of drugs in the elderly with regard to impairment of cognitive abilities. Often these patients would be prescribed several remedies at the same time for the treatment of various chronic diseases, which in the respective combination could also impair brain functions. On the one hand, diazepam is included in the "List of Essential Medicines of the World Health Organization". On the other hand, the American Geriatric Society has counted benzodiazepines among the drugs unsuitable for older people since 2012.

© Wissenschaft aktuell