The bad dream is a fundamental “relief valve” for the brain: this is what happens when the emotional control mechanism fails.
We open our eyes and here is the relief: “it was just a bad dream”: no one is chasing us, our loved ones are fine, there is no giant insect that could attack us etc.
Upon awakening, when everything becomes clear again, the dreams return to where they belong: confined to the imagination. And they are usually forgotten within minutes. But this is not always the case and the unpleasant impression left by the more negative ones can sometimes last.
Definition and differences
For a few decades, science has begun to study bad dreams. And nightmares, of course, which however are not the same thing: according to the medical definition, the latter are dreams characterized by terror or threats to physical integrity, in which visual images and emotional stress cause sudden awakening. Bad dreams, on the other hand, are considered unpleasant dream experiences, which however do not imply the interruption of sleep and are only remembered upon awakening (whether natural or caused by a noise, for example an alarm clock or a voice). In short, if you wake up suddenly, perhaps sweaty and with your heart in your mouth, it’s a nightmare, otherwise it’s not.
Frequency
After all, bad dreams are four times more common than nightmares: 90% of people say they have at least one a year, 30% one a month and 10% one a week.
And these are more women than men, while during childhood and adolescence the frequency for males and females is the same. It must also be said that – while bad dreams are almost universal – nightmares do not concern everyone: a study conducted last year at Swansea University (Great Britain) highlights that among adults there are 6-7% of people who declare they have never had even one and in general only 4.8% of women and 2.9% of men suffer from them habitually.
The narrative structure of dreams and nightmares
Studies have also shown that the two phenomena are also distinguished from each other by “narrative structure”. In fact, research conducted at the University of Montreal (Canada) shows that bad dreams are vehicles of mainly psychological threats: their dominant theme is interpersonal conflicts, misunderstandings, rejections and worries, while nightmares mainly concern aggressions, chases, disturbing presences, i.e. physical threats. A curiosity: in the Canadian study, falling into a void – which many associate with the nightmare par excellence – was found to be rare (just 1.5%), and was classified among accidents.
What are they for?
But what’s the point of the bad dream? According to currently accepted theories, all dreams have two main functions: to consolidate memories by reordering them also with respect to past experiences and to dampen the emotions linked to these memories.
And among the emotions, those that psychologically disturb us the most are certainly anger, sadness and fear: this is why the brain must stage them in order to take control of them. Thus, inevitably, in addition to good and neutral dreams, there also come bad dreams. But that’s not a bad thing.
The cathartic dream and the processing of pain
Researchers at the University of Geneva have studied the so-called “cathartic dream”: that which serves to find answers or ways out (even imaginative ones) from a situation which in reality fills us with anguish and which perhaps has no solution. These are indeed bad dreams, but with a “happy ending”, in which the protagonist somehow gets away with it, and which are often enough to reassure those who have them, even if reality does not change.
In any case, even when they don’t end with a “victory”, negative dreams work: some research has taken into consideration people who have undergone a divorce, demonstrating that, after some time, those who have often dreamed of the breakdown of the relationship are better and look back on the past with less sadness and less anger.
When the brain goes into overload
Be careful though: if the stress is too high the brain fails and here is the real nightmare. It is no coincidence that the people who most often wake up suddenly with their foreheads beaded with sweat are those who are very anxious and those who remove their problems and fears during the day by trying not to think about them, as demonstrated by a study conducted at the University of Oxford (GB) in 2017: thus the brain is forced to try to manage negative emotions only during sleep, generating dreams that are all too disturbing. In summary therefore, nightmares are nothing more than bad “unsuccessful” dreams.
Cascade of events and brain mechanisms
Although bad dreams and nightmares therefore have the same function, i.e. to free the brain from stress and re-elaborate the emotions experienced during the day (or rather: in the previous days, given that dreams can concern events that took place even 5-7 days before), the physiological mechanisms that give rise to the two phenomena are different.
In the case of bad dreams, investigations have found that there is only a decrease in activity in the medial prefrontal cortex and the anterior cingulate cortex, compared to those who have neutral dreams.
What happens in the brain during a nightmare
While during a nightmare, many more brain areas are involved in an “anomalous” way: the amygdala is hyperactive, but above all the synchronization between the activity of the neurons is very high, in particular at the level of the hippocampus, but also in the cerebellum, an area hitherto considered of little importance for emotional life. When the synchronization between brain cells is excessive it means that the brain is functioning abnormally.
However, it is the hyperactivity of the amygdala that causes the feeling of threat which in turn generates tachycardia, sweating and labored breathing, to the point of breaking the sleep paralysis and causing an abrupt awakening to try to “save oneself”. Some scholars think that the first mechanism is the physiological one, or “normal” (and you have bad dreams), while the second would be in a certain sense pathological, due to the fact that something in the nocturnal processing of emotions has gone wrong, and nightmares occur.
Imaginative Repetition Therapy
Be that as it may, there is a remedy for nightmares (especially sporadic ones not caused by serious trauma). The most effective method to remove them is called Imaginative Repetition Therapy. It’s about consciously reenacting the nightmare experienced during the night. Through imagination, we need to think of a different conclusion to the dreamed story, perhaps to make it ridiculous: the dark presence that threatened us suddenly becomes a little monster the size of a ping pong ball that we can hit with a fly swatter, for example. In practice, you need to retell the nightmare to yourself, thus transforming it into a cathartic dream, even if with your eyes open.
An effective method to overcome nightmares
It may seem trivial, but it works: a study by the University of San Diego, which in 2015 compared this method with the use of prazosin, a drug that is given mainly to people suffering from posttraumatic stress disorder to make them sleep peacefully, demonstrated that Imaginative Repetition Therapy and the drug have exactly the same effectiveness. And it usually only takes a couple of weeks to see positive results. By imagining a happy ending, nightmares become much less scary and slowly transform into simple, very useful, bad dreams.
