Circadian rhythm sleep disorders (CRSD) are characterized by an imbalance between an individual’s sleep-wake cycle and that of his own natural circadian rhythm. The body actually has hundreds of circadian rhythms; the most well known being the human’s 24 hour sleep-wake cycle. These rhythms are precisely controlled by a 'master clock' in the brain called the suprachiasmatic nucleus, or body clock.
Through external cues like light and darkness, the body releases various hormones to set the internal biological clock. When our body clock misses critical zeitgebers (external body signals), its rhythm may shift, and as a result, the body produces hormones at the wrong time or in the wrong quantity leading to circadian rhythm sleep disorders.
The general criteria for circadian rhythm sleep disorders include a persistent or recurrent pattern of sleep disturbance; sleep disturbances that lead to insomnia, excessive sleepiness, or both; and sleep disorders that are associated with impairment of function. Circadian rhythms are influenced by our age and sex. Moreover, they are affected by dietary and lifestyle factors like drinking alcohol, excess intake of caffeinated beverages, and stress. Temporary stress can lead to chronic insomnia and circadian rhythm sleep disorders.
Circadian rhythm sleep disorders can be treated with melatonin tablets. But researchers concluded that melatonin alone wasn’t powerful enough to sustain a normal rhythm. More recently, chronotherapy and light therapy have been proved to be effective. Chronotherapy reschedules or shifts the sleep/wake patterns in the hope that out-of-sync rhythms could be gradually pushed back to their normal pattern. Other researchers have realized that specialized light could also help in the control of circadian rhythms.
Apart from the above mentioned lines of treatment, sleep experts recognize the importance of advocating proper sleep habits. These include going to bed at the same time and waking up at the same time every day; bedtime preparation activities like dimming the lights an hour or so before going to bed, taking a warm bath, listening to calming music, relaxation exercises, and lowering the bedroom temperature; avoiding stimulants like chocolate, caffeinated sodas, and caffeinated teas in the evening; avoiding foods that cause acid reflux or allergic reaction that hinder sleep; and avoiding stress by means of talk therapy and meditation.