A reader asks:

 Can jet lag cause depression and anxiety? I experienced my first major depressive episode at age 26 and have been wondering whether it was triggered by chrono-biological issues related to jet lag. In August of that year, I traveled by plane from the eastern time zone of the United States to Alaska. While in Alaska for two weeks, I found myself feeling anxious, restless and disoriented from the near-constant sunlight (21 hours/day). Upon returning to the eastern time zone, I had the most terrible case of jet lag ever; it was weeks before I could re-regulate my sleep/wake cycle and appetite. Within 2-3 days of returning home, I became severely depressed, with pronounced anxiety and agitation in addition to symptoms such as depressed mood, tearfulness, hopelessness, etc. That depression responded well to medication. Since then, I have experienced major winter depressive episodes every 2-3 years. I would like to travel again, but am afraid to do so because of what happened that first time.


Jet Lag/High Latitudes=Mood Swings

Mood swings — upward or downward — are often seen in extreme cases of jet lag. Additionally, irritable hypomania — as you appear to report when in Alaska — is common during long summer days at high latitudes. The internal circadian clock can quickly drift away from the local time standard when the sun is up nearly 24 hours in summer (and also when it is down nearly 24 hours in winter at the same latitudes). Upon sudden return to “normal” day-night conditions, readjustment can be arduous. It is impossible to say whether your winter depressions in recent years might have been triggered by your difficult early travel experience. It is interesting to note that the very first SAD patient diagnosed and treated at the National Institute of Mental Health lost seasonality and became chronically depressed for two years when he returned to the States from an extended vacation in Australia.

Avoid Extreme Jet Lag/Latitude Differences

Obviously, jet lag — or sudden switches between locations with greatly different day-night cycles — can have long-term consequences for mood regulation in vulnerable people. Your occasional winter depressions might well respond to standard bright light therapy, as described on www.cet.org. Research is currently active in devising artificial light-dark schedules and medication regimens to forestall or attenuate jet lag, but as of yet there is no clear prescription (despite the claims of unscrupulous lighting manufacturers on the Web). We would advise avoiding the kind of “extreme” travel you describe, and choosing instead destinations in a similar latitude range and within a 6-hour time zone difference of your home area.