Depression, Transmissable Conditions and Why Cats Make You Mad

[tamaranth]

Ages ago, I posted about whether emotional / mental conditions might be transmissable, rather than rooted in the wiring.

I've just been reading a piece in National Geographic. Snappily titled Cat Carrier: Your Cat Could Make You Crazy*, it does actually discuss the role of infection in mental illness. The article focusses on long-term effects of toxoplasma, but there are links to some other discussions.

This one (page down to 'Microbes and Mental Illness') is quite interesting:
Psychiatric syndromes caused by infectious disease most commonly include depression, OCD, panic disorder, social phobias, variants of ADD, episodic impulsive hostility, bipolar disorders, eating disorders, dementia, various cognitive impairments, psychosis, and a few cases of dissociative episodes.

I'm taking it with a hefty pinch of salt, since it seems to encompass so very much: also, given that the page is published by the Lyme Alliance, there's an emphasis on tick-borne infections. (Should I be having vivid flashbacks to the tick-bites I suffered one summer in France, aged 10? Probably not.)

Seems to me there are four potential components:
- physical issues with nerves, brain, etc ("I am depressed because my brain doesn't work properly.")
- genetic issues ("I am depressed because my ancestors bred with the wrong people.")
- infection-related issues ("I am depressed because I caught depression.")
- environmental issues ("I am depressed because of things that have happened to me.")

When I was a lot younger I thought of depression as a kind of choice, something that could be staved off by positive thinking, therapy etc. I find it more logical, now, to think of it as an illness -- caused by some combination of those four components -- that, yes, can be treated, can be fought, but is not something to blame oneself for suffering.

I also firmly believe that depression can be a result of physical illness: that pain and infirmity (and all that results from these) can induce persistent negative states of mind. That comes under 'environmental'. I'm still thinking about the distinction between this and infectious depression.

Do any of you (especially the medical types) have any observations?

*I think this is probably a different thing to 'your cat could drive you mad', which counts as Stating the Bleedin' Obvious

Comments

[major-clanger.livejournal.com]

That there are some infections that can cause mental health problems is not in dispute (an extreme example being tertiary syphilis), although more recent suggestions that some retroviruses might cause mental illness are still being investigated. I'd not heard the suggestion that depression might be an example, though.

I tend to subscribe to what you might call a 'loading' theory of depression: we all have a certain amount of capacity for coping with stress, beyond which a depressive episode becomes much more likely. Various sorts of stress can start to fill up that capacity: immediate stress; long-term worry, physical stress from illness or chronic pain. The more of any of these are present, the less capacity there is for dealing with any of the others. Furthermore, any inherited disposition to depression might reduce the stress capacity to begin with.

I don't see this, by the way, as a simple 'top up until it spills over' model. It's more like quantum tunnelling: the lower the barrier is, the more likely that it will suddenly be penetrated. Some people will sustain a just-about manageable level of stess for a long time, whilst others will find that a combination of low-level factors will push them close enough to their capacity limit that a depressive episode becomes more likely and thus happens.

So, if someone has perhaps a mild predisposition to depression, long-term worries and stressful health problems, then they are more likely in my view to flip over to a depressive state; any addition of even moderate shorter-term stress can make this much more likely. This is my own rather empirical theory, but it does seem to fit several cases I've seen.

[marypcb.livejournal.com]

possibly add to that, that eg major changes in brain chemistry can change the permeability of the 'membrane' that the event seeps over/through

[tamaranth.livejournal.com]

The problem with things like schizophrenia and tertiary syphilis (er, apart from the obvious) is that the symptoms, the mental illnesses that may or may not be induced, happen a long time after initial infection: also, there tend to be other, more immediately obvious, physical symptoms. That old post, I seem to recall, was motivated by wondering whether one really could catch (and perhaps get over) depression in the same way as catching a cold.

The downside of that is that we'd all avoid anyone who was depressed, in case we caught it too ...

I like your loading theory: a (no doubt complex) formula combining external stress + internal propensity. Some people never seem to crack. Others crack all the time.

What about the people who are depressed for no good reason? Is that a reaction to earlier stress, or a reaction to unperceived (and maybe internal, physiological) stress?

[major-clanger.livejournal.com]

I think it can be unperceived stress, or an underlying medical factor reducing the capacity of the 'stress bucket' until it's so low that the barrier between containment and depression just disappears entirely.

Actually, 'bucket' isn't the best analogy. A better one would be a sort of tall, narrow conical hill with a well sunk into it. The closer the water is to the top, the thinner and more permeable the wall of the well is. How permeable varies from person to person; some people are fine until the well is almost full, whilst others risk leakage once there's any amount of water.

(Ooops. That nasty twanging noise is my analogy stretching well beyond its elastic limit.)

[pigeonhed.livejournal.com]

But I don't have cats... never had, never will.

Intersting concept though.

By the way, belated happy birthday. If you were in france aged 190 have you reached 200 yet? You don't look bad for your age you know...

[tamaranth.livejournal.com]

in france aged 190
fixed, thanks! and thanks for birthday wishes.

Absence of cats doesn't necessarily preclude presence of microbes, I believe. Or tics.

[pigeonhed.livejournal.com]

So even though I have no cats... i may still be insane? No its all the rest of you cat lovers that are crazy...

[tamaranth.livejournal.com]

You were the one that mentioned the cats!

Have lived without cats for over twenty years: now have cats again (though not mine). Not much difference in mental peaks and troughs since I reacquired feline company, but they're ever such good company on bad days.

[pigeonhed.livejournal.com]

There are just so many reasons I could apply to my mental well-being or otherwise. The job situation, the weather, living alone, medical aspects, listening to too much gloomy music... now I can blame tics too?

Glad the cats help. Maybe I should get a goldfish?

[marypcb.livejournal.com]

I think it's because we see the world through the lens of self that we assume self/mind is a unitary thing but it's horribly dependant on the body around the mind and the environment around the body in a way that jars once we spot noticing it, and once it starts having a more than subtle impact. I'd add environmental issues in terms of 'sick building syndrome' and SAD and recast your enviromental as experiental.

And 'all of the above' ;-)

[tamaranth.livejournal.com]

environmental and experiential are pretty much interchangeable here: I was using it to mean anything external that affects one. So, yes, SAD; sick building syndrome; crime, violence, terrorism; Other People. (See Jean-Paul Sartre for details!)