A phase II research study called IMPACT-1 tested the new drug TSND-201 (methylone) for the treatment of severe post-traumatic stress disorder (PTSD) in 65 patients who had previously been treated for PTSD[1][2]. Patients received four doses of drug or placebo at weekly intervals and were followed for 64 days[1]. TSND-201 showed statistically significant improvement in symptoms as early as day 10, with a CAPS-5 score reduction of 8 points compared to placebo[2]. At the end of the 64th day, the drug achieved an improvement of 9.64 points on this scale[1]. Among patients treated with TSND-201, 57.1% achieved a clinical response (an improvement of more than 50%), compared to only 19.2% in the placebo group[1]. 32.1% of patients treated with TSND-201 entered remission (less than 11 points on the CAPS-5 scale) compared to 11.5% in the placebo group[1]. The drug was safe and well tolerated by patients[1].