Pharmacological Treatment of Hallucinogen Persisting Perception Disorder (HPPD): A Systematic Review.
Harv Rev Psychiatry September 9, 2025 Arjen Neven, Jan Dirk Blom 3 citations
Hallucinogen persisting perception disorder (HPPD) involves lingering or recurring perceptual phenomena after substance use, which can be mild or severely burdensome. A systematic review of 31 medication studies covering 87 participants found that clonidine, clonazepam, and levetiracetam produced substantial symptom reduction in three observational studies. Among those receiving benzodiazepines, antiepileptics, antidepressants, or alpha agonists, 28% achieved full recovery and 61% partial recovery within a year. Benzodiazepines were ineffective when HPPD was triggered by lysergic acid diethylamide, and risperidone aggravated symptoms. The authors suggest these medications can treat HPPD effectively but call for randomized controlled trials and epidemiological studies.