5 ms·

It took almost a century before we figured out how photo negatives worked chemically. Didn’t stop anyone from taking photographs though. Mechanistic explanation

It took almost a century before we figured out how photo negatives worked chemically. Didn’t stop anyone from taking photographs though. Mechanistic explanations are great but not a requirement for good science.

virtualritz 3y ago
> It took almost a century before we figured out how photo negatives worked chemically. Didn’t stop anyone from taking photographs though. That argument is a strawman as it works with anything that can't be falsiefied. People who believe in astrology/chakras/etc. will also frequently tell you science will "one day" discover that "it's true". "We're just not there yet." Also consider what someone may say in a hundered years: It took almost a century before we figured out that psychotherapy didn't work. Didn’t stop anyone from taking pshychotherapy though. ;)
- stdbrouw 3y ago
  The point is that we can verify whether something works (with a randomized controlled trial) independently of knowing why it works, and psychotherapy interventions are commonly evaluated with RCTs.
- DrNosferatu 3y ago
  Psychotherapy presents itself to experimental falsification [1] with epidemiologic studies, whereas astrology/chakras/etc., do not. (Obviously, Psychotherapy is not a magic-bullet. It is however a valuable health tool to have available, and society should be educated - also on recognizing good and BAD therapeutic practices! - on how to use it, and destigmatized.) [1] https://www.cambridge.org/core/journals/epidemiology-and-psychiatric-sciences/article/is-psychotherapy-effective-a-reanalysis-of-treatments-for-depression/5D8EC85B6FA35B5CEE124381F18E51B9 https://www.cambridge.org/core/journals/epidemiology-and-psy...
  - virtualritz 3y ago
    The basic problem is that you can't do double blind studies. Because the very same person would need to be once treated, once not treated and once treated with a placebo therapy. From the same "baseline brain state". I.e. you can gather as much data as you want (referring to the metastudy you linked to) but you can't eleminate the inherent bias. People who are treated can not not know they are treated etc. And while I do believe there is are a lot of forms of psychotherapy that work, I do admit (to myself for that matter) that this is based on belief. Possibly until we can simulate brains with a "sufficient resolution" (whatever that means).
    - circlefavshape 3y ago
      You can't do a double-blind study with tobacco either. Or geology. Double blind studies are not the only source of knowledge
    - stdbrouw 3y ago
      That's not how it works, though. First, if it is not possible to blind the patient to the intervention and/or provide a meaningful placebo (which also happens with surgery and drugs with prominent side-effects) that's not a big deal, it simply changes the interpretation from "the effect of a particular regime of psychotherapy as such" to "the effect of a particular regime of psychotherapy, including expectation effects". Those expectation effects also exist in real life, if you go to a therapist you really really hope you'll get better and may be motivated to make a few changes in your life independently of the treatment, so if anything the trial becomes more realistic. Note that you'd still use a control arm so that if people get better over time without treatment, you're not exaggerating the effects of the intervention. Second, almost every randomized controlled trial compares an experimental group against a control group, you are assigned to a group and don't move between them, and what that means is that we can only compare whether the treatment works on average, not whether it worked for one person in particular because, as you say, we don't know what would have happened (counterfactually) if that one specific person had been randomly assigned to the other group. But again, this hardly matters, because we can still know how well a treatment works on average. What you refer to, an experiment in which every subject receives every treatment, is known as a crossover design and while that design has its advantages, it's not that common because it is harder to pull off and while it can be more efficient (need fewer patients to attain an estimate with a given precision) it is not "less biased" or inherently more trustworthy.

virtualritz 3y ago

> It took almost a century before we figured out how photo negatives worked chemically. Didn’t stop anyone from taking photographs though. That argument is a strawman as it works with anything that can't be falsiefied. People who believe in astrology/chakras/etc. will also frequently tell you science will "one day" discover that "it's true". "We're just not there yet." Also consider what someone may say in a hundered years: It took almost a century before we figured out that psychotherapy didn't work. Didn’t stop anyone from taking pshychotherapy though. ;)

stdbrouw 3y ago
The point is that we can verify whether something works (with a randomized controlled trial) independently of knowing why it works, and psychotherapy interventions are commonly evaluated with RCTs.
DrNosferatu 3y ago
Psychotherapy presents itself to experimental falsification [1] with epidemiologic studies, whereas astrology/chakras/etc., do not. (Obviously, Psychotherapy is not a magic-bullet. It is however a valuable health tool to have available, and society should be educated - also on recognizing good and BAD therapeutic practices! - on how to use it, and destigmatized.) [1] https://www.cambridge.org/core/journals/epidemiology-and-psychiatric-sciences/article/is-psychotherapy-effective-a-reanalysis-of-treatments-for-depression/5D8EC85B6FA35B5CEE124381F18E51B9 https://www.cambridge.org/core/journals/epidemiology-and-psy...
- virtualritz 3y ago
  The basic problem is that you can't do double blind studies. Because the very same person would need to be once treated, once not treated and once treated with a placebo therapy. From the same "baseline brain state". I.e. you can gather as much data as you want (referring to the metastudy you linked to) but you can't eleminate the inherent bias. People who are treated can not not know they are treated etc. And while I do believe there is are a lot of forms of psychotherapy that work, I do admit (to myself for that matter) that this is based on belief. Possibly until we can simulate brains with a "sufficient resolution" (whatever that means).
  - circlefavshape 3y ago
    You can't do a double-blind study with tobacco either. Or geology. Double blind studies are not the only source of knowledge
  - stdbrouw 3y ago
    That's not how it works, though. First, if it is not possible to blind the patient to the intervention and/or provide a meaningful placebo (which also happens with surgery and drugs with prominent side-effects) that's not a big deal, it simply changes the interpretation from "the effect of a particular regime of psychotherapy as such" to "the effect of a particular regime of psychotherapy, including expectation effects". Those expectation effects also exist in real life, if you go to a therapist you really really hope you'll get better and may be motivated to make a few changes in your life independently of the treatment, so if anything the trial becomes more realistic. Note that you'd still use a control arm so that if people get better over time without treatment, you're not exaggerating the effects of the intervention. Second, almost every randomized controlled trial compares an experimental group against a control group, you are assigned to a group and don't move between them, and what that means is that we can only compare whether the treatment works on average, not whether it worked for one person in particular because, as you say, we don't know what would have happened (counterfactually) if that one specific person had been randomly assigned to the other group. But again, this hardly matters, because we can still know how well a treatment works on average. What you refer to, an experiment in which every subject receives every treatment, is known as a crossover design and while that design has its advantages, it's not that common because it is harder to pull off and while it can be more efficient (need fewer patients to attain an estimate with a given precision) it is not "less biased" or inherently more trustworthy.