Table 1.

Component loadings and item selection in the exploratory dataset.

Item	Item mean (standard deviation)	PC1	PC2	h 2
Awareness of uncomfortable or painful feelings I previously avoided	2.8 (1.8)	0.82	0.03	0.67
Discovered I could explore uncomfortable or painful feelings I previously avoided	3.0 (1.7)	0.77	0.21	0.64
Awareness of dysfunctional patterns in my actions, thoughts, and/or feelings	3.3 (1.6)	0.74	0.16	0.57
Realized the nature and/or origins of my defenses or other coping strategies	2.7 (1.7)	0.74	0.31	0.64
Realized how current feelings or perceptions are related to events from my past	3.3 (1.6)	0.72	0.17	0.55
Discovered a clear pattern of avoidance in my life	2.4 (1.8)	0.70	0.20	0.53
Gained resolution or clarity about past traumas or hurtful events	2.4 (1.9)	0.67	0.29	0.53
Gained a deeper understanding of events/memories from my past	3.2 (1.6)	0.66	0.35	0.56
Realized I could experience memories previously too difficult to experience	2.0 (1.8)	0.65	0.29	0.50
Discovered how aspects of my life are affecting my well-being	3.7 (1.4)	0.64	0.32	0.51
Realized ways my beliefs may be dysfunctional	3.3 (1.7)	0.62	0.17	0.42
Discovered clear similarities between my past and present interpersonal relationships	2.5 (1.8)	0.61	0.36	0.51
Realized how critical or judgmental views I hold towards myself are dysfunctional	3.1 (1.7)	0.59	0.34	0.47
Realized certain actions I should take in regards to important relationships in my life	3.2 (1.7)	0.50	0.44	0.45
Discovered new feelings or perspectives about significant relationships in my life	3.5 (1.6)	0.46	0.45	0.41
Realized the point of view or actions of others that had been difficult to understand previously	3.0 (1.7)	0.45	0.36	0.33
Awareness of my life purpose, goals, and/or priorities	3.6 (1.5)	0.09	0.72	0.53
Awareness of beneficial patterns in my actions, thoughts, and/or feelings	3.1 (1.5)	0.23	0.70	0.54
Experienced validation of my life, character, values, or beliefs	3.5 (1.5)	0.10	0.67	0.46
Realized the importance of my life	3.6 (1.6)	0.09	0.67	0.45
Discovered clarity or creative solutions about how to solve a problem in my life a	3.0 (1.7)	0.36	0.63	0.53
Awareness of information that helped me understand my life	3.9 (1.3)	0.23	0.62	0.44
Discovered new actions that may help me achieve my goals	3.1 (1.6)	0.32	0.60	0.46
Discovered ways to see my problems with more clarity	3.5 (1.6)	0.45	0.58	0.54
Discovered new insights about my work or career	2.2 (1.9)	0.23	0.53	0.33
Discovered specific techniques for coping with difficulties	2.8 (1.7)	0.40	0.51	0.41
Gained a deeper understanding of previously held beliefs and/or values	3.7 (1.3)	0.23	0.51	0.31
Discovered a vivid sense of the paradoxes in life	3.5 (1.6)	0.17	0.50	0.28

PC1: loading onto the first principal component; PC2: loading onto the second principal component; h²: item communality, or the sum of the squared factor loadings for a given item.

Items means (standard deviations) were not statistically different in the psilocybin and LSD subsamples (data available upon request). Items are sequenced by loading on PC1. Italic font indicates five items that were removed due to loading 0.4 or more on both factors after the first or second principal component analysis. Bolded coefficients indicate items retained in the final questionnaire from each principal component. The full questionnaire with items, response options, and scoring instructions are available in supplementary materials or from the corresponding author.

^aThis item loaded ⩾0.4 on both factors based on the second principal component analysis after removing the first four items based on the first principal component analysis.