Figure 1. Treatment Outcomes of Ketamine vs Electroconvulsive Therapy (ECT) Stratified by Less or More Severe Baseline Depression Severity .

The least-squares mean from mixed-effects model analyses was plotted for both treatment groups (ECT and ketamine) based on the 16-item Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR16) baseline depression severity thresholds of moderate severe or severe (score of ≤20) or very severe (score of >20), in which scores range from 0 to 27, with more than 20 indicating very severe depression. EOT indicates end-of-treatment visit.