Table 2.

Characteristics of flashback phenomena

Study	Subject	Gender	Age	Administration after which flashback occurred	Other administrations before onset of flashback	Domain	Number of flashbacks	Description of phenomena	Duration	Onset after administration	Last occurrence after administration	Circumstances	Interpretation	Impairment of daily life	Reoccurrence at follow-up
NCT02308969	1	f	28	0.1 mg LSD	-	Visual, auditory	2	Visual pseudohallucinations, changed perception of music	5 min	2 days	-	Listening to music	Neutral	No	Unclear (1)
NCT03019822	2	m	27	0.1 mg LSD	40 mg amph	Visual	1	Visual pseudohallucinations	Secs	~ 7 days	-	Waking up	Positive	No	No
	3	m	25	0.1 mg LSD	40 mg amph, 125 mg MDMA	Emotional	1	Positive mood	1 min	1 day	-	Listening to music	Positive	No	No
NCT03321136	4	f	40	0.2 mg LSD	0.05 mg LSD	Visual, self-structure	4	Visual pseudohallucinations, feeling of disintegration of the self	Secs	1.5 days	4.5 days	Falling asleep	Distressing	No	No
	5	f	30	0.05 mg, 0.1 mg, 0.2 mg LSD	25 mcg LSD	Visual, cognitive	3	Intensified perception of colours, slowed thinking	Hours	1 day	-	No specific	Neutral	No	No
NCT01878942	6	f	27	0.2 mg LSD	-	Visual	1	Intensified perception of colours	Secs	3.5 days	-	Unclear	Unclear	No	No
	7	f	52	0.2 mg LSD	-	Visual	1	3D perception of a 2D object	Secs	1.5 days	-	Reading	Positive	No	No
NCT03912974	8	f	26	25 mg psilo	-	Visual	1	Visual pseudohallucinations	Secs	2.5 days	-	Dinner	Neutral	No	No
	9	f	25	25 mg psilo	2 × 10 mg escitalopram	Visual	1	Altered perception of light	Secs	17 days	-	Falling asleep	Distressing	No	Unclear (1)
NCT03604744	10	f	25	30 mg psilo, 0.2 mg LSD	15 mg psilo	Emotional	4	Euphoric mood	Secs	2 days	6 days	Waking up	Positive	No	No
	11	m	29	0.1 mg LSD	0.2 mg LSD, 15 mg psilo	Visual	1	Visual pseudohallucinations	1 min	2 days	-	Relaxing	Neutral	No	No
	12	f	26	0.2 mg LSD	30 mg psilo, 15 mg psilo, 0.1 mg LSD	Visual	~ 30	Visual pseudohallucinations	Secs	1 day	7 months	No specific	Positive	No	Yes
	13	f	48	30 mg psilo	0.1 mg LSD	Visual	~ 20	Visual illusion	Secs	1 day	-	No specific	Neutral	No	No

(1): please see results. amph d-amphetamine, f female, m male, psilo psilocybin, min minutes, secs seconds