Jet lag is a travel-induced circadian rhythm disorders. Symptoms of jet lag include difficulty sleeping at the new sleep time, daytime sleepiness and fatigue, and impaired performance. Treatment of jet lag includes both behavioral and pharmacological component. A short-half-life benzodiazepine hypnotic for several nights at the new sleep time have been recommended to decrease jet lag symptoms. Melatonin also can alleviate jet lag and bright light exposure is a useful countermeasure for jet lag.

<jats:p>The jet lag syndrome is a phenomenon of modern social life that occurs due to a mismatch between the body's natural circadian rhythm and the external environment due to rapid travel across multiple time zones. Jet lag syndrome symptoms are primarily related to sleep disturbance, interfering with travellers' social life and vocational performance. The symptoms usually last for a few days but can be for a week depending upon the changes in time zones. During the jet lag, abrupt shifts in the environmental light-dark cycle temporarily desynchronize the suprachiasmatic nucleus (SCN) of the hypothalamus downstream oscillatory networks from each other, resulting in increased sleepiness and impaired daytime functioning. Eastward travel is associated with a longer duration of jet lag than westward travel. Polysomnographic data show that jet lag results in changes in sleep-wake timing and different aspects of sleep architecture. This circadian misalignment can lead to a cluster of symptoms, including signicant metabolic, cardiovascular, psychiatric, and neurological impairments.[1] Light is the major entrainment factor for the circadian clock, and timed bright light exposure at the appropriate portion of the light-dark cycle is the principal non-pharmacological approach. Nutraceuticals and pharmacological therapies include melatonin, melatonin receptor analogues (agonists), non-benzodiazepine hypnotic agents, caffeine, diphenhydramine (e.g., Benadryl, McNeil; Aler-Dryl, Reese), and armodanil. The awareness about the jet lag syndrome, planned sleep schedule before departure and phase resetting by exposure to light or medication can help travellers overcome this condition. New research suggests that modication of clock function via genetic manipulation may one day have clinical applications.[2] The current perspective of the COVID-19 pandemic resulted in many countries imposing a lockdown, reducing sunlight exposure and altering daily social schedules. Therefore, it essentially leads to changing 'time zones' without actually travelling across time zones, causing social jet lag.[3]</jats:p>

The circadian system regulates the cyclical occurrence of wakefulness and sleep through a series of oscillatory networks that comprise two different theoretical processes. The suprachiasmatic nucleus (SCN) of the hypothalamus contains the master oscillatory network necessary for coordinating these daily rhythms, and in addition to its ability to robustly generate rhythms, it can also synchronize to environmental light cues. During jet lag, abrupt shifts in the environmental light–dark cycle temporarily desynchronize the SCN and downstream oscillatory networks from each other, resulting in increased sleepiness and impaired daytime functioning. Polysomnographic data show that not only does jet lag result in changes of sleep–wake timing, but also in different aspects of sleep architecture. This type of circadian misalignment can further lead to a cluster of symptoms including major metabolic, cardiovascular, psychiatric, and neurological impairments. There are a number of treatment options for jet lag involving bright light exposure, melatonin, and use of hypnotics, but their efficacy greatly depends on their time of use, the length of time in the new time zone, and the specific circadian disturbance involved. The aim of this review is to provide mechanistic links between the fields of sleep and circadian rhythms to understand the biological basis of jet lag and to apply this information to clinical management strategies.

Jet lag syndrome appears after multiple time zone transitions as bodily rhythms shift out of phase with the local environment. The possible psychiatric complications of jet lag have been underinvestigated. In the present review, the symptoms of jet lag in the general population, the chronobiological aspects of psychosis, as well as a possible correlation between jet lag and psychosis are discussed. The conclusions are that jet lag, through disruption of biological rhythm and probably sleep deprivation, may yield an exacerbation of existing psychotic conditions. The evidence concerning the appearance of de novo psychosis triggered by jet lag is inconsistent and far from convincing.