The Truth behind the Nightmare...

             You feel completely panicked.  Your legs feel sluggish and heavy, so you never seem to be running fast enough.  You finally make the decision to turn around and face your attacker.  He’s holding an axe and calmly making his way towards you.  Now he’s towering over you with a menacing smile on his face and slowly lowering the axe, and then…you wake up.  This particular plot may not seem familiar, but feeling these sort of fearful emotions during sleep may.   At some point, most people have experienced at least one nightmare in their lifetimes.  The standard definition of nightmare is a dream that causes a strong negative emotional reaction, such as fear, terror, anger, embarrassment, etc.  A nightmare may elicit such responses because it may contain events that are extremely dangerous, emotionally painful, or psychologically disturbing. (1)

                Dreams occur during particular stages of sleep. (3) These stages are defined by the presence or absence of the background electrophysiological rhythms that are recorded in the EEG  (electroencephalogram).  Dreams are reported based on their associated electrophysiological rhythms that characterize certain sleep stages.  Dreams, in general, are usually associated with REMS, rapid eye movement sleep.  During this state the brain activity is most similar to wakefulness, so it is assumed that dreams occur at this time.  In contradiction to this assumption, it has been proven that cognitive dreaming can occur in the sleep stages that are not during REMS, and REMS can occur without dreaming.  Therefore, it can be concluded that REMS is but one of multiple electrophysiological markers that can be associated with sleep.  Other electrophysiological events that occur in association with sleep are PGO spikes (pontine electrical bursts of activity); saw-tooth waves of the EEG which can occur during REMS for some people; and hippocampal theta EEG frequencies. (5)

As opposed to dreams in general, nightmares are known to exclusively occur during REM sleep.  They tend to arise during the longer and later REM phases in the latter part of the sleep cycle. It has been hypothesized, but not yet proven, that the dream content during REMS is more “bizarre and hallucinatory” than the dream content from the other sleep stages. (5)  I guess this can be researched by exploring the brain activity of each stage of the sleep cycle.  Yet this may be an issue because that would mean boundaries would need to be set in order to define when a stage terminates and when the next one begins. (2)

Nightmares may be mistaken for night terrors, but there are significant differences.  As stated above, nightmares occur during REMS, but night terrors arise outside of the REMS phase so they occur early in the night.  The mental content of nightmares tend to be complex, whereas the mental content of night terrors are prone to be “sparse or absent” so those who go through it may not even remember what scared them. (5) Usually nightmares can be recalled afterwards, but night terrors cannot.  It is also more difficult to wake the individual that is having the night terror.  It is more likely for those having night terrors to sleep walk, perform vocalizations, and to excrete waste.  Ultimately, night terrors and nightmares may be a product of frightening dreams, but they are two completely different phenomena.(2)

There are some factors that make the occurrence of nightmares more likely; one of which is certain drugs.  It is predominantly medications that induce sleep or insomnia that induce nightmares.  For example, medications known to suppress REM sleep lead to REM rebound episodes when the individual goes through medication withdrawal.  REM rebound episodes can also occur as a result of withdrawal from addictive drugs.  It is these REM episodes that are associated with nightmares.  I wonder if there can be an easier transition to stop using these sorts of medications without bringing about REM episodes.  Maybe if the REM sleep was still being suppressed but in lesser degrees over time then the REM episodes would not be as sever. There are primary neurotransmitters that affect sleep and dreaming: acetylcholine, norepinephrine, serotonin, dopamine, and GABA. (5) Most drugs that neurochemically affect any of these neurotransmitters would make the manifestation of nightmares more likely.  Out of all the clinical prescription medications, beta blockers, which affect norepinephrine receptors, are most prone to the induction of nightmares.  Antidepressants, which increase serotonin levels, are also known to cause nightmares.  When there is acute withdrawal from some antidepressants, intense visual dreams and nightmares have been reported. (2)

Another factor that would make individuals more prone to nightmares is if they have some sort of psychological problem, such as post-traumatic stress disorder (PTSD) or depression.  PTSD is an anxiety disorder that arises as a result of an extremely traumatic event. (4)  Nightmares may be manifested as a result of this mental illness because the emotions from this event may be too intense for the person to process.  Because of this inability to emotionally integrate, the person will have reoccurring nightmares of the traumatic experience so they will be continuously reliving it.  The dreams of the depressed individuals tend to contain more traumatic and somber content compared to the nondepressed.  Research has shown that the depressed individual’s dreams also contain more failure and misfortune compared to a schizophrenic.  For depressed suicidal patients, it is more common for their dreams to contain death themes.  Nightmares are correlated with these illnesses because they are both affected by similar neurotransmitters such as serotonin. (6)

Overall, it is my opinion that the dream/nightmare is emotionally parallel to what we conceive as “reality”.  I say this because it appears that the situations in our lives and the emotions we go through affect the type of dreams that we have.  It has been shown that major life stresses or, as mentioned above, some mental illnesses may bring about nightmares.  If this is true then the nightmare reflects the sort of emotions you are going through in life.  Therefore, it appears that the dream/nightmare is an internal emotional “reality”.  The content of the dream may be objectively unrealistic or unlikely, but the feelings throughout the dream are an actual entity.  Yet even the events occurring in the dream seem real when the individual is actually experiencing it because the senses are active during the whole process.  One has the ability to see, touch, hear, taste, and smell during his dream, just like the person would in life.  Descartes states that if something cannot be scientifically classified, studied, measured, or “logically” proven to exist then it’s not a dream. (5)  I disagree because this implies that there is one standard of reality, and if a state exists outside of these criteria then it technically doesn’t exist because it is not “real”, it’s a dream.

References

1)      Nightmare Web site: http://en.wikipedia.org/wiki/Nightmare

        2)       Nightmares-Symptoms, Treatment, and Prevention Web site:    http://www.healthscout.com/ency/68/612/main.html

     3)       Dreams Web site: http://en.wikipedia.org/wiki/Dream

     4)       Sleep Disorders-Nightmares are a Treatable Disorder Too Web site: http://www.healthcentral.com/sleep-disorders/c/68/13253/disorder/

     5)       Pagel, J.F. (2008). The Limits of Dream: A Scientific Explanation of the Mind/Brain Interface. Burlington, MA: Elsevier.

6)      Kramer, Milton (2007). The Dream Experience: A Systematci Exploration. New York, NY: Routledge.