A transdiagnostic state measure of rumination over the previous two weeks consisting of 9 items on a 5 point Likert scale from 0 (Never/Rarely) to 4 (All The Time).

Changes in resting-state activity during functional magnetic resonance imaging(fMRI) scans.

Participants are shown words one at a time and asked to answer if each of the words apply to 'Self' or 'Other'.

Changes in activity in the default mode network during functional magnetic resonance imaging(fMRI) scans while participants perform a self-attribution task.

Montgomery-Åsberg Depression Rating Scale (MADRS) is a 10-item clinician rated scale measuring depression severity

Montgomery-Åsberg Depression Rating Scale (MADRS) is a 10-item clinician rated scale measuring depression severity

The C-SSRS will be used to assess suicide potential or tendency as a study entry criteria and monitored throughout the study.

The Yale-Brown Obsessive Compulsive Scale Modified for Body Dysmorphic Disorder (BDD-YBOCS) is a 12-item, semi-structured, rater-administered measure that assesses body dysmorphic disorder severity during the past week. Scores for each item range from 0 (no symptoms) to 4 (extreme symptoms); the total score ranges from 0 to 48, with higher scores reflecting more severe symptoms.

Proportion of patients with adverse events (AEs)

The EDE is a structured clinical interview (investigator rated) used to measure severity of the characteristic psychopathology of eating disorders

A TEAE is defined as an adverse event (AE) that has an onset on or after the dose of study drug, or any pre-existing AE condition that has worsened on or after the dose of study drug.

Change in Montgomery-Asberg Depression Rating Scale (MADRS) total score from Baseline to 3 weeks post psilocybin administration. The minimum and maximum MADRS total score values are 0 and 60 and a higher score means a worse outcome.

MADRS is a clinician-rated scale measuring depression symptom severity, consisting of 10 items, each scored from 0 (normal) to 6 (severe), for a total possible score of between 0 to 60; higher scores denote greater severity. Response \>= 50% decrease and remission \<= 10 total score.

MADRS is a clinician-rated scale measuring depression symptom severity, consisting of 10 items, each scored from 0 (normal) to 6 (severe), for a total possible score of between 0 to 60; higher scores denote greater severity. Response \>= 50% decrease and remission \<= 10 total score.