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Overview
About the Causes of 25-Hour Sleep CycleAlthough a 25-hour sleep cycle affects very few people in the world, this phenomenon has been studied by scientists for decades, and is even mentioned in the tenth revision of the "International Classification of Diseases." By contrast, standard sleep cycles remain positioned at 24 hours to approximately 24 hours and 20 minutes. Several reasons may account for the unusual length of the 25-hour cycle, some of them being internal and some being external in nature.
The Biological Clock
As humans, we are born with a circadian pacemaker hardwired inside of our brains. This pacemaker has a scientific name: the suprachiasmatic nucleus. Even rodents have such a biological clock hardwired in their own brains. This suprachiasmatic nucleus influences our sleep cycle by regulating the release of chemicals into our body. Although scientists are still puzzled as to how these chemicals instigate the sleep cycle, they have observed a relationship between activity triggered by the suprachiasmatic nucleus and sleep patterns.
Exposure to Light
The mind's clock, the suprachiasmatic nucleus, uses optical input in order to function. This explains why humans and animals exhibit rapid eye movement (REM) during sleep--even during sleep, we receive information through our eyes. If a mammal is deprived of this circadian clock (either through injury or from prolonged exposure to light), the mammal will have difficulty maintaining a regular sleep schedule, and thus may tend to adopt a 25-hour sleep schedule.
Time Zones
Not surprisingly, changing times zones will have a direct effect on your sleep patterns. Human nature constantly seeks to conform to a standard routine. A traumatic break in routine will leave your brain desperately trying to reorient itself. While waiting to stabilize, your sleep cycle may exceed its normal time range and reach 25 hours or beyond.
Physical Disorders
Since much of the activity stimulated by the suprachiasmatic nucleus is chemically-based, an imbalance of certain chemicals may cause an abnormality in a subject's sleep pattern. Two important chemicals affected by the sleep process are cortisol and melatonin. If these chemicals are either too abundant or too scarce during the sleep cycle, they may exert undue influence on the cycle and cause it to either shorten or lengthen.
Psychological Causes
Depression will often cause people to sleep longer as they attempt to function in the absence of motivation. Many of the body's illnesses originate in a person's psychology. A person's emotional outlook is closely related to his physical health, causing a person to attempt to resolve emotional issues by seeking a quick fix on a physical level. Thus, oversleeping is one way that people sometimes attempt to compensate for feelings of discouragement.
