Neuropsychological profiles of patients suffering from hallucinogen persisting perception disorder (HPPD): A comparative analysis with psychedelic-using and non-using controls
Georg Leistenschneider, Tomislav Majić, Simon Reiche, Thomas Riemer
Scientific Reports December 31, 2024 DOI: 10.1038/s41598-024-82216-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case-control study Peer reviewed |
|---|---|
| Sample size | 24 |
| Population | Individuals with HPPD and matched controls with and without prior psychedelic use |
| Topics | Psilocybin |
| Keywords | Neuropsychology Hallucinogen Neuropsychological assessment Neuropsychological test Perception Clinical psychology Cognition |
| Citations | 3 |
| Key findings | Some individuals with HPPD showed below-average visual memory and executive function, but adjusted comparisons with controls revealed no significant differences. |
Abstract
Abstract Classic psychedelics like LSD and psilocybin are showing promising effects in treating certain psychiatric disorders. Despite their low toxicity and lack of an addictive potential, in some individuals, psychedelics can be associated with persisting psychological harms. Hallucinogen Persisting Perception Disorder (HPPD) is one of those complications, a rare disorder characterized by enduring perceptual symptoms without impaired reality control. While the phenomenological aspects of HPPD have been characterized, the neuropsychological consequences have remained understudied. This study probes the neuropsychological profiles of eight individuals with HPPD, utilizing a comprehensive test battery. Performance is benchmarked against normative data and compared with two control groups, each comprising eight matched subjects—with and without prior psychedelic use. The assessment of individual performances revealed below average results in tests of visual memory and executive function in some subjects. No significant differences were observed in alpha-adjusted comparisons with controls, whereas unadjusted analyses were suggestive of impaired executive functions among HPPD patients. Together, these preliminary results underline the need for further focused research into the neuropsychological dimensions of HPPD.