shorter days, higher depression

Silenceisbliss

I think this is the correct place to post my question...

So, I was discussing with my sister the other day that the days are getting much shorter, it’s dark for much longer, and naturally everyone is getting much more tired and depressed now during the short dark days of winter.

As a psychologist, my sister was telling me that suicide rates are increasing now with decline in sunlight, and as I know also this is a commonly accepted fact.

I proposed to her the possibility of the depression also having a biological/natural element to it due to the decrease of oxygen levels at this time of year, but she brushed it off without a second thought.

I would be curious to hear what you lot would make of this theory?

My arguement:
The cold weather now in the autumn/winter has the leaves on the trees brown and stripped, vegetation in general is at its annual minimum. Therefore photosynthesis is less proficient. Days are getting much shorter, sunlight is present for only a few hours a day, therefore again; photosynthesis is less proficient. This should seem to mean that there will be a lesser concentration of oxygen in the air to breathe. On top of this, we are currently getting polar winds from the north, which by their nature have a lesser concentration of oxygen.

So, there’s a slightly less oxygen concentration during the autumn/winter months…. Could this possibly be contributing to the mood changes and energy levels we witness in ourselves and others? Or are the mood and energy levels soley relient on the levels of lighting from the sun?

We are susceptible to very slight variations in atmospheric gases after all are we not?

Any input would be appreciated

tallaght01

I don't think there is less oxygen in the atmosphere in winter, though.

I'm open to correction.

Silenceisbliss

I too am still to find data somewhere which backs up lower oxygen levels, but to me it seems to make plausible sense. Ill continue searching

Silenceisbliss

absolutly nothing to be found on the net at all to disprove or to prove seasonal fluctuations in oxygen levels.....I guess this is "outside of the box" so...

never the less, it still seems logical to me to assume that the oxygen concentration in the lower atmoshere will fluctuate with seasonal change, if only even minutely.

Alun

Air is denser at lower temperatures though, so per volume of air inhaled you'll get more oxygen that way and my guess is that this would counteract any seasonal reduction in oxygen levels, if there even is one.

Anyway, I always though that increased incidence of depression in winter months was down to lack of sunlight (Google SAD - Seasonal Affective Disorder).

EamonnKeane

The oxygen fluctuation is incredibly tiny. CO2 rises by 4 ppm in winter, so O2 would presumably drop by the same, which is nothing (O2 is 210,000 ppm as it is).

I dunno if air pressure could affect it - I always thought it was odd that, in school, people would generally agree that a certain day went by quickly or slowly - how did they all experience it the same way? Could air pressure affect one's perception of time?

And I always thought that suicide rates were higher in summer, for whatever reason.

Kevster

I believe that you should be looking more into the area of there being less sunlight available during the Winter months with which to produce Vitamin D. Vit. D is produced in the skin from the reaction of UV light with dehydrocholesterol. It is a vitamin which has been linked to depression in the past and, with less sunlight, there will be less of it in our bloods.

Of course, you have to realise that the cold temperatures, rain, and snow also add inconveniences to a person's day - conveniences which may just tip a person over into a depressive state.

I'm normally depressed year-round, but my mood has dipped a lot within the past week.

sam34

suicide rates are highest in the springtime. always a favourite mcq in the membership exams!

John

Your body produces melatonin in response to darkness. During the day its production is inhibited but as it gets darker, levels of melatonin increase. Melatonin controls your circadian rhythm and is synthesised from tryptophan. So with shorter days you get more melatonin being produced and therefore your store of tryptophan is going to decrease.

Now here's the kicker, tryptophan is also the precursor to another chemical called serotonin. Serotonin is an important neurotransmitter involved in many different pathways (controlling satiety, homeostasis and, most pertinently to this discussion, mood). Serotonin is believed to be reduced in depression and the most common drugs used to treat depression work by increasing levels of serotonin (and other neurotransmitters).

So I think that over the course of winter, overall levels of tryptophan can become reduced due to increased production of melatonin. As a result, levels of serotonin might be compromised. This probably doesn't cause an immediate effect but I reckon it takes its toll over a longer time period (it takes a while for increased levels of serotonin to alleviate depression following drug treatment). Therefore, depression might only kick in later in the season and reach its peak in the spring (and therefore account for the statistic given above by sam34).

woop

John wrote: »

Your body produces melatonin in response to darkness. During the day its production is inhibited but as it gets darker, levels of melatonin increase. Melatonin controls your circadian rhythm and is synthesised from tryptophan. So with shorter days you get more melatonin being produced and therefore your store of tryptophan is going to decrease.

Now here's the kicker, tryptophan is also the precursor to another chemical called serotonin. Serotonin is an important neurotransmitter involved in many different pathways (controlling satiety, homeostasis and, most pertinently to this discussion, mood). Serotonin is believed to be reduced in depression and the most common drugs used to treat depression work by increasing levels of serotonin (and other neurotransmitters).

So I think that over the course of winter, overall levels of tryptophan can become reduced due to increased production of melatonin. As a result, levels of serotonin might be compromised. This probably doesn't cause an immediate effect but I reckon it takes its toll over a longer time period (it takes a while for increased levels of serotonin to alleviate depression following drug treatment). Therefore, depression might only kick in later in the season and reach its peak in the spring (and therefore account for the statistic given above by sam34).

biochemist?

taram

If we were so affected by oxygen levels then being indoors lots/air conditioning, even having a severe cough/chest infection would affect the amount of oxygen you're getting, and those people would likely be depressed. I find it's the biting cold early in the morning and having to take the bus inside of cycling that puts me in a bad mood.

DrIndy

woop wrote: »

biochemist?

neuroscientist

Bally8

As far as I remember from my psychology degree its more related to seritonin than oxygen. I cant even come close to explaining it as well as Dr. Indy but oxygen has never even been considered a causal agent as far as I know.

seanybiker

John wrote: »

Now here's the kicker, tryptophan is also the precursor to another chemical called serotonin. Serotonin is an important neurotransmitter involved in many different pathways (controlling satiety, homeostasis and, most pertinently to this discussion, mood). Serotonin is believed to be reduced in depression and the most common drugs used to treat depression work by increasing levels of serotonin (and other neurotransmitters).

Woo thats why Im on seroxat. dont have enough serotonin or something like that. Thats why me nerves are always at me
Im on the highest dose now for the last while and not really noticing much of a change to be honest.

DrIndy

oxygen has not been considered a causal agent and logically, with air movements, stratospheric winds and no significant change in respiration in the winter (although sunlight is less and thus photosynthesis is less - this is countered by decreased temperatures reducing plant and animal respiration rate. many animals either migrate or hibernate)

The key is the circadian cycle and the exposure of sunlight.

John has very succintly given a scientific explanation for this.

There is an element of adaptation to this though - people born in high latitudes with significant decreased sunlight in the winter have less problems with this than people who move to these areas from further south. Iceland has a very low incidence of SAD although they now have plenty of other things to be depressed about!

John

DrIndy wrote: »

neuroscientist

A 10th level Neuroscientist. I'm close to levelling up too :pac:

DrIndy wrote: »

Iceland has a very low incidence of SAD although they now have plenty of other things to be depressed about!

I don't think even SSRIs can help them!

DrIndy

John wrote: »

A 10th level Neuroscientist. I'm close to levelling up too :pac:

Wearing your hat+2

andrewh5

Alun wrote: »

Anyway, I always though that increased incidence of depression in winter months was down to lack of sunlight (Google SAD - Seasonal Affective Disorder).

Correct. You can buy special light boxes to go on your desk if you are affected - the cost about €100.

DrIndy

There is good evidence for "natural sunlight" lamps aiding in SAD and it certainly is better than drugs.

(awaiting psychiatry opinion............)

sam34

i cant give a definitive opinion on these lamps, as i have yet to read much about them.
but, from my experience, a lot of depression we see is not SAD, it is either reactive or endogenous, but not seasonally related. in my time in psychiatry, i have never seen anyone with a cyclical, seasonal pattern to their depression.

thats not to say im dismissing SAD, or the lamps.light therapy, but its not something i've come across.