Analysis of cerebrovascular dysfunction caused by chronic social defeat in mice, 2020, Lehmann et al.

NIH blog Psychological stress damages brain’s blood vessels by Brandon Levy

https://irp.nih.gov/blog/post/2020/07/psychological-stress-damages-brain-s-blood-vessels

 

Anyone else find it remarkable that those mice can answer psychometric questionnaires? I mean, this is truly amazing. How is this not a major discovery? Those mice are incredible!

Because that's the only way depression and anxiety are "diagnosed" in humans. Since, you know, there is no test or reliable signs and symptoms. Unless, of course, those are simply invalid and based entirely on superficial features of the kind that would not differentiate between sleep, locked-in syndrome and coma.

A human bully can inflict physical trauma on another human. Is it hypothesized that in mice this is impossible? That the microbleeds are not the result of blunt force. I really doubt the mouse bullying takes the form of mental anguish or insulting their mama.

Imagine if physics worked this way. All you need to "prove" you have a perpetual heat machine is to ask a bunch of people to confirm that it "feels" warm. QED. What more can anyone expect? We'd basically still at horses and buggies but it would be super easy to publish major breakthroughs.

 

Yes it's in mice but it would be great if they could make some progress on the biology of depression and anxiety.

 

I would have guessed that mice experience chronic social defeat due to their terrible pick-up lines...

 

You know, honestly, I think they should just leave those mice alone. Many of the "rodent models" of psychopathology are really questionable, and I don't think they have a lot to say about actual human conditions like depression and anxiety. I don't think we should be subjecting creatures to such suffering without very good justification.

For one, there is the problem of inferring psychological states from rodent behaviours. Believe it or not, there's a rodent model of schizophrenia, and one of autism! How on earth can we infer such complex conditions, just based on behaviours like how close a mouse likes to get to other mice. Or whatever. As for depression and anxiety, it would help if we first had a reasonable formulation of what we meant by those in humans, before we go about torturing mice (I think the current diagnostic categories are loose to the point of being useless).

For another, there is the problem that they do these really extreme interventions, that involve great physical and well as psychological harm, and then attribute all the outcomes to psychology (for example "maternal deprivation" studies involve leaving the pups without food or water for a critical period of their infant lives, that's bound to mess up your brain development).

A third issue I have is that the hypotheses are trite and essentially always posed in the same direction - can we show that this that, or the other terrible "stress" or "trauma" will have some sort of measurable effects on health? Its a body of work that has no place for equipoise (everyone is a believer; nobody is interested in demonstrating that these things don't cause such outcomes). Of what practical value is this relentless search for yet another demonstration of a terrible health outcome from some sort of stress? Do we really need health psychology to tell us that its not a good idea to deprive babies of food and water for an extended period when really young? Or can we just use our humanity for that? Ditto for psychological stress. We should want to ease the suffering of people in situations where they feel disempowered, helpless and afraid. We don't need health psychology to tell us that. But not eliminate stress altogether. Life is full of demands, pressures, distress, pain and suffering, and isn't that part of the journey?

 

Basic biological processes can be elucidated from mice experiments and it is perfectly possible that chronic stress causes physical damage to the body and it would have been good to get an answer from a properly conducted test.

But you can only talk about the biology of stress if you place all your animals in the same stressful situation then look at all of them to see what damage they have. Then you can say that 50% of stressed animals have damaged blood vessels or whatever. You can't pick out some mice and expect it to tell you anything useful.

Animal experiments should only be used in a very limited way when nothing else would do, not carelessly in work designed to prove a hypothesis.