The Sample Characteristics dataset includes information on the participants who are included in the studies. This information is provided at the study level—meaning, data are not broken down into the specific treatment arms such as the intervention or control groups. Use this dataset if you want to learn more about the number of participants in the study; inclusion and exclusion criteria related to substance use and suicidality; baseline clinical characteristics such as PTSD severity, trauma type, military status, and comorbidities; and, basic demographic information such as age, gender or race for the sample as a whole (not individual participants). Visualizations made from this dataset will be based on the 389 RCTs included in the PTSD-Repository. Values reported as "NA" or not reported "NR" by the study are null values (empty cells). Data is at the study level.