Why are sleeping pills associated with an increased risk of dementia?

There’s an interesting study published in the British Medical Journal this week which concerns the relationship between use of drugs known as benzodiazepines and risk of dementia in elderly individuals [1]. Benzodiazepines are drugs which are usually used to treat anxiety and/or insomnia (diazepam – trade name Valium – is an example). In this study, benzodiazepine use was associated with about a 50 per cent increase in risk of dementia.

The authors of the study concluded that: “Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drug class in the general population, indiscriminate widespread use should be cautioned against.”

It may indeed by the case that benzodiazepine drugs have the capacity to damage the workings of the brain and bring on dementia. This study does not prove this, however, because it is ‘epidemiological’ in nature. This means that the study has found an association between benzodiazepine use and dementia, but that does not mean that the drugs are causing the dementia. It might be that the real cause of the problem is other factors that are themselves associated with benzodiazepine use. In this study, some potential so-called ‘confounding factors’ were taken into consideration. However, this adjustment is an imprecise science and the end result is still something that only tells us that benzodiazepine use and dementia are linked.

Coincidentally, this week I came across a study in which dementia-prone mice (due to genetic glitches in their make-up) were subjected to exercise (running on a wheel), melatonin therapy (melatonin the chief brain chemical which regulates sleep) or both [2] Compared to no intervention at all, the mice subjected to one or both of the interventions over time ended up doing better in terms of learning, behaviour and memory.

Some researchers have previously put forward the theory that melatonin may help to counter the pathological processes thought to be involved in the development of Alzheimer’s disease [3]. Noting in nailed down in this area just yet, but the possibility exists that low melatonin levels may predispose to dementia. Of course, low melatonin levels will also predispose to insomnia too. So, might the association between benzodiazepine use and dementia be, at least in part, because those with melatonin ‘deficiency’ are more likely to suffer from insomnia and more likely to be treated with benzodiazepines as a result?

We’re unlikely ever to be able to unravel this, but I do think it’s good that the role of melatonin in health appears to have attracted more interest in recent years. Melatonin secretion is responsive to light. Getting decent light exposure in the day (particularly the morning) is one way to ensure enough melatonin is made when the evening comes. However, as I discussed recently here, light exposure in the evening (from room lighting or electronic devices) has the capacity to suppress melatonin secretion. Keeping light exposure low in the hours before bed may therefore promote good sleep and might possibly help us maintain our mental faculties as we age too.


1. Billioti de Gage S, et al. Benzodiazepine use and risk of dementia: prospective population based study BMJ 2012; 345 doi: 10.1136/bmj.e6231 (Published 27 September 2012)

2. García-Mesa Y, et al. Melatonin plus physical exercise are highly neuroprotective in the 3xTg-AD mouse. Neurobiology of Aging, 2012; 33 (6): 1124

3. Rosales-Corral SA, et al. Alzheimer’s disease: pathological mechanisms and the beneficial role of melatonin. J Pineal Res. 2012 Mar;52(2):167-202

7 Responses to Why are sleeping pills associated with an increased risk of dementia?

  1. Norah Ethel Coleman 28 September 2012 at 5:22 pm #

    I totally agree with you, Dr. Briffa. And what about people who really need to take some kind of stuff in order to get a good night´s rest ? Do they offer another solution ? No, just the scary part and let your life quality go down hill. Not being able to sleep well, due to pain – in my case – yes, would certainly drive me to dementia !!!

  2. Alison 28 September 2012 at 6:13 pm #

    I agree Dr Briffa, Benzodiazepines might well be associated with dementia but they are not the cause. I suggest the true cause of dementia is the inability to adsorb vitamin B12 which, amongst other insidious symptoms, presents as insomnia, anxiety (hence benzos) and hormone disruption, including hormones that regulate sleep.
    GPs will check B12 levels if a patient suspects deficiency. Be aware, that plentiful evidence exists that many people have B12 deficiency and yet present with normal results in blood serum. It is now widely accepted that lab reference ranges as set too low in the UK as reported recently on Radio Four and The Times newspaper. Age is irrelevant, this is NOT as commonly thought, a tiresome and benign disease of the elderly and vegans. Doctors would be best advised to treat according to symptoms, thereby preventing serious neurological damage as has proven to be the case in numerous untreated patients with borderline deficiency. The younger generation, our children and those under 50 are being overlooked by clinicians’ lack of age- old and forgotten knowledge of this devastating disease. The consequences of late diagnosis are often irreversible with young lives damaged forever.

    See ….Are you B12 Deficient, here: ..http://www.b12d.org/content/are-you-b12-deficient

    And symptom checker: http://b12d.org/content/b12-signs-symptoms-assessment

    For help and more information see Registered Support Groups http://www.b12d.org and http://www.pernicious-anaemia-society.org/. The Pernicious Anaemia Society is referenced as a main point of reference for patients suffering with B12 deficiency by the Health Authority.

    Thank you Doctor Briffa for highlighting the connection between melatonin, benzodiazepines and dementia, we give you the cause.

  3. Lori 29 September 2012 at 1:39 am #

    My mom got hooked on benzos when she was in rehab recovering from surgery. The thing is, they didn’t help her sleep. Guess what did: melatonin plus valerian–little pills from the grocery store!

    I didn’t make the connection between the Xanax and my mom’s nervousness and other symptoms until I read the book Anatomy of an Epidemic. It presents evidence that those pills can make you mentally ill.

  4. Chris 1 October 2012 at 3:54 pm #

    Well said Nora,
    persons experiencing pain could inquire of their physicians (GPs) if inflammation could be an aspect promoting their pain. They could inquire if the presence of inflammation could be factor in the level of pain they experience and if the persistence of inflammation has any bearing upon the persistence of pain. They could wonder, patient and physician alike, if dietary and lifestyle aspects could be promotional of inflammation or otherwise hinder healing. Patient and physician alike might read the ‘Earthing’ book (Ober, Sintra, Zucker) so they could have an informed discussion upon its directions. The patient could try ‘earthing’ and together patient and physician could try to discern if the practice has a helpful bearing upon pain of any bearing upon sleeplessness. On Amazon reader reviews largely indicate ‘earthing’ is beneficial where pain, inflammation, and sleep issues are concerned.

  5. Karen 1 October 2012 at 7:23 pm #

    Given the already well established problems relating to benzodiazepine use, you would hope that there would be no need to advise doctors against “indiscriminate widespread use”.

  6. Ted Hutchinson 1 October 2012 at 11:13 pm #

    Free download not just for PC or laptop monitor but also for iPhone, iPad, and iPod touch
    f.lux: software to make your life better
    remember any LED display at night will reduce your melatonin secretion.

    One of the reasons melatonin is neuroprotective is it’s role as an iron chelator.
    All Men and older women build up excess iron stores over time, melatonin, curcumin help keep us safe from Iron behaving badly.

    Regularly donating blood also reduces the chance of iron overload.

  7. Georgia Ede MD 9 October 2012 at 12:07 am #

    Very interesting; yes, so important to point out when studies are epidemiological in nature–essentially these are just guesses, at best, as to what the underlying reason for the association might be. I am a psychiatrist who prescribes benzodiazepines regularly, however, I also offer nutrition consults to my patients who are interested in alternatives to medications, and have had some luck treating panic and anxiety disorders with low glycemic index and low carbohydrate diets. Given that a high glycemic index Western diet puts people on an invisible hormonal roller coaster, which in turn triggers spikes in adrenaline levels, it stands to reason that carbohydrate-sensitive people can feel very anxious, irritable, tense, or panicky in between meals, especially in the early evening, before dinner. You described this phenomenon very nicely in a podcast last year. So, could it be that one reason why people who take benzodiazepines are more prone to dementia might be because they are more anxious–as a result of their being more prone to carbohydrate-related issues…of which dementia is emerging as yet another example? To be clearer–could both anxiety and dementia simply be two faces of the same coin–namely, chronically elevated and unstable blood sugar and insulin levels?

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