They did not have a placebo-receiving control group.
All the other points you mentioned seem very relevant, but I somewhat disagree with the importance of a placebo control group, when it comes to estimating counterfactual impact. If the control group is assigned to standard of care, they will know they are receiving no treatment and thus not experience any placebo effects (but unlike you write, regression-to-the-mean is still expected in that group), while the treatment group experiences placebo+”real effect from treatment”. This makes it difficult to do causal attribution (placebo vs treatment), but otoh it is exactly what happens in real life when the intervention is rolled out!
If there is no group psychotherapy, the would-be patients receive standard of care, so they will not experience the placebo effect either. Thus a non-placebo design is estimating precisely what we are considering doing in real life: give an intervention to people, who will know that they are being treated and who would just have received standard of care (in the context of Uganda, this presumably means receiving nothing?).
Ofc, there are issues with blinding the evaluators; whether StrongMinds has done so is unclear to me. All of your other points seem fairly strong though.
Thx for commenting. I have to agree with you and disagree somewhat with my earlier comment. (#placebo). Actually placebo-effects are fine and if a placebo helps people: Great!
And yes, getting a specific treatment effect + the placebo-effect is better (and more like in real life), than getting no treatment at all.
All the other points you mentioned seem very relevant, but I somewhat disagree with the importance of a placebo control group, when it comes to estimating counterfactual impact. If the control group is assigned to standard of care, they will know they are receiving no treatment and thus not experience any placebo effects (but unlike you write, regression-to-the-mean is still expected in that group), while the treatment group experiences placebo+”real effect from treatment”. This makes it difficult to do causal attribution (placebo vs treatment), but otoh it is exactly what happens in real life when the intervention is rolled out!
If there is no group psychotherapy, the would-be patients receive standard of care, so they will not experience the placebo effect either. Thus a non-placebo design is estimating precisely what we are considering doing in real life: give an intervention to people, who will know that they are being treated and who would just have received standard of care (in the context of Uganda, this presumably means receiving nothing?).
Ofc, there are issues with blinding the evaluators; whether StrongMinds has done so is unclear to me. All of your other points seem fairly strong though.
Thx for commenting. I have to agree with you and disagree somewhat with my earlier comment. (#placebo). Actually placebo-effects are fine and if a placebo helps people: Great!
And yes, getting a specific treatment effect + the placebo-effect is better (and more like in real life), than getting no treatment at all.