Figure 1. Study design.
Ketamine group was administered clinical scales and received an MRI at three time points (T1: pre-treatment/baseline, T2: 24 hours post-first infusion of ketamine, and T3: 24–72 hours post fourth infusion of ketamine). The study length varied from 2–2.5 weeks depending on which day the first infusion started on. Fifty non-depressed healthy controls (HC) received an MRI at baseline (T1) and a subset of the fifty (n=17) HCs received a repeat assessment 2 weeks after T1.