Why we need sleep without pills

It has long been known among experts in the field of dementia that taking certain medications regularly increases your risk of developing the condition.

Among the culprits that have been associated with an increased risk of dementia are sleeping tablets, including temazepam and ‘Z’ drugs (zolpidem and zopiclone). But this is a controversial topic for two reasons.

One is that the finding is not universal (some studies do not show this is the case) and the other is that there may be other variables that might be influencing the risk: that is, something else about people who use these medications that causes a higher risk of dementia, rather than the medication itself.

In the case of sleeping tablets, this might be that the person is more anxious and depressed (so, not sleeping well) and these conditions themselves might be increasing the risk of dementia, or even a harbinger of the condition.

In trying to unravel the complexity, looking at how a medication might increase risk can be illuminating. It is this that piqued my interest recently when a study was published that looked at zolpidem, and specifically its effect on  deep sleep.

I have discussed in a previous column a wonderfully elegant mechanism that is initiated when you are in the deepest stages of slumber. This is known as the glymphatic system – similar to the lymphatic system but made up of glial  cells in the brain (giving the ‘g’ at the start of the word). The glymphatics are responsible for washing your brain. This might sound ominous, but it is a critical part of brain health and maintenance.

Every metabolic process in the body, including in the brain, results in the build-up of debris – particles that, if not removed, may cause damage to the cells. The glymphatic system is the waste disposal unit that completes this removal.

Among the debris that needs to be cleared is amyloid – the accumulation of which in the brain is considered to be a critical part of the pathway that leads to Alzheimer’s dementia.

Studies have shown that even one night of sleep deprivation results in a build-up of amyloid, as it has not been cleared properly. If this is happening consistently over a long term, it is a worry.

One of the chief mechanisms by which the glymphatics works is through the small blood vessels in the brain pulsing regularly.

This pulsatility pushes fluid from  the blood into the brain matter. It then travels across the brain, collecting the debris and amyloid on its way, before being drained away.

Where does zolpidem fit in? Well, the recent study showed that this medication reduces the pulsatility through affecting noradrenaline: a chemical in the brain.

Here, then, we have a plausible explanation about how the medication might cause the problem.

Insomnia is an extremely common problem and in itself is a risk factor for dementia if severe and prolonged.

Sleeping tablets are used by many people. Their occasional use is not a problem when it comes to dementia, but if they are used regularly and over a long time, this is a concern to me.

It might feel as if you are caught between the devil and the deep blue sea, but it is important to understand where medications fit in when it comes to managing sleeplessness and not lose sight of all the other things you can do to help promote sleep: exercising, managing stress, seeing the early morning light, reducing bright lights (and screen time) in the evening, sleeping in a cool and quiet environment, avoiding caffeine beyond noon and alcohol, and so on.

All these are elements of good sleep hygiene. If you are contemplating taking sleeping tablets, or are on them already, don’t forget to discuss with your doctor the pros and cons and other strategies for managing poor sleep.

 Kailas Roberts is a psychogeriatrician and author of Mind Your Brain: The Essential Australian Guide to Dementia, available at bookstores and online. Visit yourbraininmind.com or uqp.com.au