The hidden health messages in dreams

YOU might be one of those people who ‘never’ dreams. But, in fact, we all do, every night — it’s just that some of us remember dreams better than others. This may be down to when we wake up in the sleep cycle.

Our most vivid, intense and bizarre dreams occur in rapid eye movement (REM) sleep — the period at the end of the 70 to 90-minute sleep cycle; this state of sleep is very similar to the awake brain.

We dream in both REM sleep and non-REM sleep, which makes up most of our night’s rest. But dreams in REM tend to be longer and more vivid. It’s unclear why.

We usually wake naturally from REM sleep so we may remember for a short time the last dream we experienced.

As for their content, dreams usually draw from our experiences — often recent ones — at some very basic level.

A current theory is that dreaming is a by-product of memory formation and problem solving — and REM sleep, particularly, is when we process emotional experiences that cause us stress when we are awake.

In this sense dreams may act as a ‘safety valve’ for a buildup of emotional worries. But we don’t really know.

However, there is no doubt that dreams can be linked to some medical conditions.

There is a group of sleep disorders, known as parasomnias, that involve unwanted experiences while you fall asleep, when you are sleeping or as you are waking up. Parasomnias may include abnormal movements, behaviours, emotions, perceptions or dreams. They include so-called night terrors, which typically involve sitting up in bed and shouting, possibly lashing out.

Another parasomnia, REM sleep behaviour disorder, is where you act out vivid dreams during REM sleep.

Normally, the body is paralysed during this stage of sleep, but in this disorder the mechanism fails, so dreams are accompanied by lots of action and the dreamer may even be violent. Devoted husbands have attacked and even killed their wives, mistaking their wife for an intruder during this dream state. The disorder has also been the basis for acquittals. However, it is not to be confused with sleepwalking, where the sleeper does not act out their dreams. When woken from an episode of REM sleep behaviour disorder, the individual often recalls many details of the vivid dream.

The disorder is more common in people with certain conditions. It occurs in about 50 per cent of those with Parkinson’s, and is even as high as 95 per cent in some forms of dementia.

Parasomnias arise from altered brain circuitry. Some people are more likely to sleepwalk or have other parasomnias when they are feeling stressed.

Nightmares are a side-effect of some medications, so check the leaflet that comes with your prescription.