Psychiatric morbidity and time zone changes: a study of patients from Heathrow airport.
Level 4 - case-series / case-control
Retrospective case series of psychiatric hospital admissions from a single airport.
PubMed 7093591 · doi:10.1192/bjp.140.3.231
What was done
The authors analyzed 186 patients admitted over a two-year period from Heathrow Airport to the nearest psychiatric hospital, evaluating the relationship between psychiatric diagnosis and direction of flight/time zone changes using Fisher's exact probability test.
What was found
Depression was diagnosed significantly more often after east-to-west flights compared to west-to-east flights (P < 0.012) and compared to north-to-south combined with south-to-north flights (P < 0.015). Hypomania was inversely related to depression in an east-to-west comparison (P < 0.025). No other diagnostic categories were associated with travel direction. Schizophrenia accounted for 93 (50%) of all admissions (24 of whom had been aimlessly wandering) and represented 20% of all schizophrenic admissions to the hospital during that timeframe. Twenty patients had at least one prior admission under similar circumstances.
Why it matters
This study provides early observational evidence suggesting that circadian disruption from transmeridian flight may differentially trigger or precipitate affective episodes depending on travel direction.
Limits
The study is a single-center retrospective case series without a control group of unaffected travelers or denominator data on total passenger volumes by flight route. Confounders such as pre-existing psychiatric history, medication adherence, flight duration, and sleep deprivation were not controlled for in the abstract.
Cited by
- supports A study conducted at Heathrow Airport found a significantly higher risk of passengers presenting with psychotic mania when traveling eastward from America compared to traveling westward from Asia.