Frequent air travellers, such as cabin crew who repeatedly take long-haul flights, risk ill health, a study says.
As well as the obvious jet lag encountered with crossing multiple time zones, an out-of-kilter body clock can trigger psychotic and mood disorders.
The researchers say disrupted sleep and hormone patterns are largely to blame, The Lancet reported.
The Liverpool John Moores University team reviewed over 500 published articles on aviation and health.
They found reports of cabin crew experiencing decreased cognitive performance and mental health problems, including brief episodes of psychosis - loss of contact with reality.
And air hostesses complain of menstrual cycle problems linked with the irregularity of their work.
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