Some people report experiencing more vivid dreams within days of reducing their caffeine intake. What's going on?

Have you recently cut down on caffeine and feel like you're having the most vivid dreams of your life?

While there are a number of potential benefits of reducing our caffeine intake – such as whiter teeth and fewer trips to the toilet – we often hear one downside of cutting back on caffeine is the emergence of vivid (and sometimes scary) dreams.

It's a strange and specific effect that many people say kicks in within days of reducing caffeine intake.

But is there actually any science behind this? Let's look at what the research can tell us.

Caffeine is a stimulant that makes us feel alert and awake. It works by blocking a chemical in our brain called adenosine.

Adenosine usually builds up during the day while we're awake and active. By the evening, the build-up of adenosine in our brains helps us to feel sleepy. Adenosine gets cleared away while we sleep and we wake ideally feeling refreshed, ready for the adenosine to build up again.

When we have caffeine, it blocks adenosine's signal. So, while the adenosine is still there, we don't feel the sleepiness as strongly. When the caffeine wears off, our urge to sleep increases (the caffeine crash).

Caffeine has a half-life of around three to six hours, meaning half the caffeine we consume is still in our body after this time and, importantly, still affecting adenosine. That's why, for many people, having caffeine in the afternoon or evening can make it harder to fall asleep at night.

By interfering with our adenosine signalling, caffeine can also make our sleep more disrupted and reduce the overall amount of sleep we get. This is especially true for our deep, restorative non-rapid eye movement (NREM) sleep. Overall, the research clearly shows the later we have caffeine and the more we have, the worse it is for our sleep.

There's not a lot of direct research on whether cutting down on caffeine makes our dreams more vivid. Most studies focus on how caffeine affects sleep rather than what happens in our dreams.

But that doesn't mean we're totally in the dark. We know sleep quality and dreaming are closely linked.

Even though there's no direct proof, people keep saying the same thing: they cut back on caffeine and within a few nights, their dreams start feeling more vivid, detailed, or just plain weird.

While cutting back on caffeine will not directly cause........

© BBC