Editing Jet lag (section)

=== Mental health implications ===
Jet lag may affect the mental health of vulnerable individuals. When travelling across time zones, there is a "phase-shift of body temperature, rapid-eye-movement sleep, melatonin production, and other circadian rhythms".<ref name="young">{{cite journal |last1=Young |first1=D. M. |year=1995 |title=Psychiatric morbidity in travelers to Honolulu, Hawaii |journal=Comprehensive Psychiatry |volume=36 |issue=3 |pages=224–228 |doi=10.1016/0010-440x(95)90086-b |pmid=7648847}}</ref> A 2002 study found that relapse of [[Bipolar disorder|bipolar]] and [[psychotic disorders]] occurred more frequently when seven or more time zones had been crossed in the past week than when three or fewer had been crossed.<ref name="katz">{{cite journal |last1=Katz |first1=G. |last2=Knobler |first2=H. Y. |last3=Laibel |first3=Z. |last4=Strauss |first4=Z. |last5=Durst |first5=R. |year=2002 |title=Time zone change and major psychiatric morbidity: the results of a 6-year study in Jerusalem |journal=Comprehensive Psychiatry |volume=43 |issue=1 |pages=37–40 |doi=10.1053/comp.2002.29849 |pmid=11788917}}</ref> Although significant circadian rhythm disruption has been documented as affecting individuals with bipolar disorder, an Australian team studied suicide statistics from 1971 to 2001 to determine whether the one-hour shifts involved in daylight saving time had an effect. They found increased incidence of male suicide after the commencement of daylight saving time but not after returning to standard time.<ref>{{cite journal |last1=Berk |first1=Michael |last2=Dodd |first2=Seetal |last3=Hallam |first3=Karen |last4=Berk |first4=Lesley |last5=Gleeson |first5=John |last6=Henry |first6=Margaret |date=January 2008 |title=Small shifts in diurnal rhythms are associated with an increase in suicide: The effect of daylight saving |journal=Sleep and Biological Rhythms |volume=6 |issue=1 |pages=22–25 |doi=10.1111/j.1479-8425.2007.00331.x}}</ref>