Why Do I Have Disturbing Dreams?
Disturbing dreams can be found in various sleep disorders or parasomnias like a nightmare, night terror, etc. The exact cause for such sleep disorders has not been found or attributed to any organic or biochemical abnormality and only the hypothetical theories have been put forward for it. According to a recent theory, the serotonin neurotransmitter deficiency is thought to be associated with maximum sleep disorders which are based on the fact that the selective serotonin reuptake inhibitor group of drugs is used as the treatment for such conditions.
The brain pathway attributed for the night terrors is activation of the thalamus cingulate pathway which is associated with the emotional response of the brain, hence increasing the involvement of different type of emotions in it. It is accompanied by persistent deactivation of the thalamocortical pathway which is responsible for arousal or awakening from the sleep and provides reasoning to the thinking. The active involvement of these pathways along with the limbic system is seen on SPECT (single-photon emission computed tomography) studies.[1]
Few studies have also shown that night terror are commonly associated with migraine, stress, fear, organic brain causes, etc. Other common external causes can be watching television till late night, disruptive sleep schedule, history of travel, horror movies, concurrent illness, sleeping with a full bladder, drug-induced, etc.[2] It is associated with few other symptoms like teeth grinding or bruxism seen in second stage of NREM sleep, sleepwalking, sleep talking, hypersomnolence, etc.
Night terrors also known as pavor nocturnus, are classically a non-rapid eye movement sleep disorder usually encountered in middle hours of sleep when the 3rd and 4th stage of NREM sleep is predominant and is characterized by fearful, panic-stricken, emotionally dysphoric arousal from the sleep due to an unlikable, dangerous, life-threatening dream with severely dysphoric emotional moments. It is usually confused with nightmare which is a REM sleep disorder and is very important to be differentiated from it. The classical feature is that the person is unable to recall the events and is much more panic-stricken as compared to a nightmare.
What Age Do Night Terrors Start?
The exact age is not specified for their onset but these are also seen in younger age group specially children similar to that of nightmares. The most common age group is between 4 to 12 years in children and 20 to 30 years in adults. The prevalence of sleep terrors is between 1 to 7% in children which is much lower as compared to that of a nightmare. A similar trend is found with the prevalence in adults which ranges between 2 to 3% and is lower when compared to the prevalence of other sleep disorders.
The children suffering from night terrors below the age of 4 years are likely to have a serious disorder with peak frequency of episodes as 1 per week whereas above this age group the frequency decreases to 1 to 2 episodes per month. The prevalence of night terrors in elderly age group is much lower and lies below 1%.[1]
Another difficulty inaccuracy and correct assessment of the studies is that the survey is subjective and younger children below 2 years of age are unable to describe it making it impossible to study that age group. Most of the people recover from this disorder till adolescence while only a few cases are such which have their first episode in adulthood.
Conclusion
Even after the availability of new technological advances, the research is limited in this area because it is a subjective description based on an individual’s experience and confounding cannot be eliminated completely. The age group associated with these disorders is predominantly of young age which makes it even more difficult to do the research. Any specific cause has not been established yet for sleep disorders like night terrors etc. and only hypothetical theories have been put forward to fill the void of research.
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