New form of magnetic brain stimulation eliminates severe depression within days

I just read the study that you talked about. Here is the link to the full paper for those that are interested: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142912/.

While there was no significant difference between treatment and sham groups in the sample overall, there was a significant difference between the treatment group and the sham group when those with comorbid PTSD were removed from the sample. In this case, significantly more people in the treatment group experienced remission than those in the sham group. In other words, the ineffectiveness of TMS may have been more due to the effects of PTSD.

As far as finding an unbiased study with natural variation, this is why control groups are so important. If you have a control group, then you can account for the natural variation in illness course, as you are comparing using an actual treatment vs. letting the illness run its course.

/r/science Thread Parent Link - med.stanford.edu