OPINION: Sorry to rub it in, but I’m in an airport again. Sydney International, waiting for my connection. Apparently, it’s about 7pm in Sydney, but it’s dark outside and my body’s telling me it’s really 9pm. Next transfer is in Dubai, apparently around 6am; who knows what my circadian system’s going to think by then.
Your circadian system is your internal 24-hour body clock, and when your body clock doesn’t match the actual time of the place you’re in, that’s jetlag. Or, in technical terms, a circadian rhythm sleep-wake disorder. And it’s not all in your head, either – when you’re jetlagged, your body isn’t producing all the right hormones at all the right times, including melatonin, which plays a role in getting you ready for a kip.
Everyone knows what jetlag feels like, even if you’ve spent your whole life in the same time zone. Ever stayed up a couple hours later on Friday and Saturday night because they’re not work nights? Yep, that’s all it takes to jetlag you. First thing I’ll be doing when I’m next outside an airport is to get me some sunlight to reset my body clock.
Another “disorder” that scientists think is linked to an out-of-phase circadian system is seasonal affective disorder, or SAD. There’s still a little bit of residual cynicism over whether SAD really exists, but a majority of the clinical and academic communities agree it’s a thing.
Perhaps some of the cynicism is because SAD seems new and faddish. It was first described in clinical literature less than 40 years ago (along with the first proposed treatment, but I’ll come back to that).
Another cause for cynicism is its “twilight state” as not quite a formal disorder in its own right. By that I mean you can pick up the diagnostic bible, the DSM-5, and find nary a chapter devoted to SAD.
Where you will find it is as a specifier or subtype of depression proper. There are pros and cons to this – it is really important that it is diagnosed appropriately to rule out “normal” depression, which also can have a seasonal element in getting worse during winter. It could be mistaken for bipolar disorder, which sees cycles of up and down mood. Or it could be “just” typical depression.
But because there isn’t a big illuminated sign next to SAD, there’s research to suggest that frontline medical practitioners may not think of it. This is important, because the frontline treatment of choice for SAD is quite a bit different from “normal” depression.
You already know, or can guess, what that frontline treatment is: light therapy, first described in the mid-1980s. There’s now quite a bit of evidence that it’s effective for most people, and can even prevent the onset of serious depressive episodes if people start when they begin to feel the seasonal blues.
Early prescriptions were to stare at a bright light for three hours in the morning, but these days, 45 minutes appears to be enough. Heck, a 45-minute walk has proven helpful. The recent discovery of a “new” photoreceptor in our eyes that is tuned to blue light has led to speculation that blue-tinged light may be better than standard white light, but research on this is as yet inconclusive.
Which brings me back to circadian rhythms. It’s estimated that 1-10% of any national population will experience SAD. That’s quite a range, which may be because where you are in the world is important. SAD is about twice as common in the US than in Europe and, perhaps more significantly, it’s more prevalent in northern US states –places that have shorter days in winter. This has led to speculation that SAD is a circadian out-of-phase issue.
If you think this might be you, ask your GP or, alternatively, head over to the Mental Health Foundation’s SAD webpage.
Where to get help:
If it’s an emergency and you feel that you or someone else is at risk, call 111.
- Need to talk? Free call or text 1737 any time for support from a trained counsellor
- Suicide Crisis Helpline – 0508 828 865 (0508 TAUTOKO)
- Lifeline – 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP)
- Youthline – 0800 376 633, free text 234 or email talk@youthline.co.nz or online chat
- 0800 What’s Up - 0800 942 8787
- Samaritans – 0800 726 666
- Depression Helpline: 0800 111 757 or free text 4202 to talk to a trained counsellor, or visit depression.org.nz
- Anxiety New Zealand - 0800 269 4389 (0800 ANXIETY)
- Healthline – 0800 611 116
- Additional specialist helpline links: https://www.mentalhealth.org.nz/get-help/in-crisis/helplines/
