Psilocybin vs Escitalopram for Major Depressive Disorder: Comparative Mechanisms

Patients were tested with functional magnetic resonance imaging (fMRI) to measure brain brain responses to emotional faces before and after the treatment. The 2 values of BOLD signal (before and after exposure to emotional faces) were used to estimate a percentage value per patient and then these were used to estimated a group percentage change.

Change in QIDS-16 (self-rated measure of depressive symptoms). Scale is composed of 16 items that correlate with the 9 Diagnostic Statistical Manual (DSM-IV) symptom criteria for depression. Each response is graded 0-4 (none-severe symptoms). Questions 1-4 concern sleep disturbances, Question 5 addresses sad mood, Questions 6-9 appetite/weight, Question 10 concentration, Question 11 self-criticism, Question 12 suicidal ideation, Question 13 interest, Q14 energy/fatigue and Questions 15-16 psychomotor agitation/retardation. All questions that address the same topic are grouped and only the highest score from each group is summed up together with the other questions in order to produce a total score. Scores can range from 0-27 and depression severity is graded based on the total score in the following way: 1-5 = No depression 6-10 = Mild depression 11-15 = Moderate depression 16-20 = Severe depression 21-27 = Very severe depression

Lower score =better outcome (less depression)

HAMD-17: clinician rated Hamilton Depression Scale of depression severity. Range of scores: 0-52: where 0-7 is normal, 8-16 is mild, 17-23 is moderate, >23 is severe.

A threshold score of 17 is the entry: a score of 17 or higher indicated moderate-severe depression and was a requirement for entry into this trial at the screening point. This baseline does not refer to the screening point, it refers to the HAMD conducted 7-10 days before psilocybin dosing.

A higher decrease in the HAMD (larger negative change score) is a better outcome.

BDI-IA: patient-rated Beck Depression Inventory, depressive symptomatology scale. Higher score = worse depression. The total score range is 0-63: where 0-13 is considered minimal range, 14-19 is mild, 20-28 is moderate, and 29-63 is severe

Higher negative score = greater decrease in depression scores 6 weeks after each treatment arm = better outcome.

MADRS - Montgomery-Asberg Depression Rating Scale, clinician-rated measure of depression. This scale is clinician-rated and consists of 10 items; each item is rated on a 0-6 scale, resulting in a maximum total score of 60 points, with higher scores indicative of greater depressive symptomology.36 The MADRS scoring instructions indicate that a total score ranging from 0 to 6 indicates that the patient is in the normal range (no depression), a score ranging from 7 to 19 indicates "mild depression," 20 to 34 indicates "moderate depression," a score of 35 and greater indicates "severe depression," and a total score of 60 or greater indicates "very severe depression."

A higher decrease in the MADRS (larger negative change score) is a better outcome.

Number of patients who "responded" on the QIDS-16 scale (Quick Inventory of Depressive Symptomatology, self-rated). "Response" is defined by a decrease in QIDS score of 50% from baseline.

Higher number of patients who responded = better outcome for treatment arm.

Number of patients who "remitted" on the QIDS-16 scale (Quick Inventory of Depressive Symptomatology, self-rated). "Remission" is defined by having a QIDS score below 5 at the 6 week point = no depression.

Higher remission rate = better outcome (less depressed patients after treatment)