This is Pragmatic Follow-Up Part A for Episode 21 Daylight Saving. I'm John Chidjie.
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So I had some feedback from, via the feedback form, from Andrew McAuliffe, I think it's
pronounced, I hope I'm getting that right, please correct me if I'm not, regarding the
issues of seasonal affective disorder.
Now I didn't go into much depth into that in the episode, we're just talking about the
mechanics of daylight saving rather than its effect on people, but it's a very good point.
I actually, I did consider talking about it, but I didn't end up putting it in the episode.
So now that I've had some feedback about it, I think it's relevant to talk about it just
briefly at least.
And seasonal affective disorder, there's a link in the show notes to tell a bit more
about it.
The idea is that people's moods will change based on the seasons.
So during summertime, everything's all, there's a lot of sunlight, it's all bright and green.
Well presumably, unless there's a drought on, or unless you live in the middle of the
desert in any case, whereas in winter it is you know it's cold, there's less
sunlight because the days are shorter, everything is brown or looks like it's
dead or dying, at least that's the way I describe Calgary in the
middle of winter anyway. Mind you there's a fresh beautiful sprinkle of
snow on the ground, it's a beautiful fairy tale white and that's of course
before it turns into slush and then it kind of breaks that little illusion but
But anyway, bottom line is that SAD, Seasonal Affective Disorder, affects a not insignificant
percentage of the population.
It's less common in countries like Australia, however it generally seems to be in temperate
and sub-temperate or sub-arctic climates.
But the funny thing is that if you look at it in relation to daylight saving, there doesn't
seem to be much of a direct connection. So having a look into this, what
would cause seasonal affective disorder? The most predominant theory is that it's
about the body's internal body clock, sometimes referred to as the circadian
rhythms. And there have been a bunch of studies that have shown that there seems
to be a bit of a weak link between the amount of light that your eyes are
exposed to during the day and a disruption of the body's natural circadian rhythms.
So you would think that a person's latitude where they live would heavily influence this.
Now what they've done, a group of people have done a bunch of studies, these are linked
in the show notes if you want to have a look into it.
There's a study of people that lived in Fairbanks, that's in Alaska and it's very close to the
Arctic Circle. And they basically in summertime they get, and in the worst part of wintertime,
they get only four hours of sunlight. Of that, that's not even full strength sunlight either,
that'll be including your twilights. So, with only four hours of sunlight each day, and
they then compared that with a town in New Hampshire, and this particular one I looked
that didn't specify the town,
but let's just say in New Hampshire.
And New Hampshire has, in the worst part of the winter,
nine hours of sunlight,
which is still not a lot really, but more than double.
Now you would think that there would be more impact
on the people living in Fairbanks,
more people would have SAD than they would in New Hampshire,
but that is not the case.
So the study concluded that approximately 9%
of people in Fairbanks were diagnosed with a form,
and ranging from mild to severe,
but a form of seasonal affective disorder.
And it was exactly the same percentage,
or if not, I think it was within about 6.7% of that
was found in New Hampshire to have SAD.
So statistically, I think it was more actually.
I think it was on 9.6 or 9.7%.
I didn't write down the number,
but the point is that that's counterintuitive.
And this is the problem,
is that people say daylight saving must have an impact
on people's circadian rhythms.
But if it's true, surely that would happen
'cause daylight saving will come in in the summertime
and you have to wake up early and when it's darker.
But because it's brought in at a time at which
it'll be darker for the first few weeks of daylight saving,
if you normally got up at six in the morning,
but days are getting longer and longer.
So the point at which you're in the middle
of daylight saving, you'll be getting up,
it'll still be sunlight in most places.
So it would only ever be a temporary situation.
It would it be confusing to the body?
Probably, but would it throw your circadian rhythms out,
your body clock out?
I'm not convinced that it would, not significantly.
If it was noticeable and detectable,
would only be brief. So there have been plenty of studies into this. It's not
conclusive but it seems to suggest that there is either a very weak link or
there is in fact perhaps no link. So in any case I want to thank Andrew for
bringing that one up and it was something that I did consider addressing
and now I have addressed that. So thanks for the feedback Andrew, really appreciate it.