This unregistered trial (n=14) was an open-label prospective case series of clonazepam for LSD-induced hallucinogen persisting perception disorder with anxiety features in young adults, which demonstrated significant and sustained symptom relief.
This synthetic trial has been added to our database because a psychedelic paper (about a clinical trial) references this trial, but no (live) registration can be found.
The study investigated the efficacy of clonazepam in treating sixteen young adults (ages 17–24) experiencing hallucinogen persisting perception disorder (HPPD) following LSD use. Participants had experienced HPPD symptoms and associated anxiety for at least three months and had been drug-free for the preceding three months. The intervention involved a two-month course of clonazepam, titrated up to 2 mg per day, followed by a gradual taper.
Clinical outcomes were assessed using the Clinical Global Impression Scale, a Self-Report Scale for HPPD severity, and the Hamilton Anxiety Rating Scale. Results indicated that patients experienced significant relief from perceptual disturbances and anxiety during the treatment phase. These improvements were notably sustained throughout a six-month follow-up period after the medication was discontinued.
Open-label administration of clonazepam for 2 months, followed by a gradual taper and a 6-month follow-up.
Initial titration phase: started at 0.25 mg b.i.d., individually raised up to 2 mg b.i.d. by the end of the first week.
Maintenance phase: 2 mg/day for the remainder of the 2-month treatment period.
Discontinuation phase: 0.5 mg weekly over 1 month to prevent rebound-relapse symptoms.