Hallucinogen persisting perception disorder in adolescence: a complex case of lysergic acid diethylamide-induced visual disturbances with trauma-associated exacerbation
Neuroscience Applied January 1, 2026 A. Fernandez Ribas, V. Pérez Rodríguez, M. Paduraru
Hallucinogen Persisting Perception Disorder (HPPD) affects 1-5% of psychedelic users, with higher rates among recurrent LSD consumers and synthetic cannabinoid users. The disorder involves persistent visual disturbances such as palinopsia and visual snow, linked to 5-HT2A receptor dysfunction and visual cortex hyperactivation. About 20% of cases become chronic, often tied to early onset and polysubstance use. A 16-year-old developed HPPD after a second LSD use, with visual snow, micropsia, and altered object outlines that were episodic and triggered by trauma-related situations, causing significant distress and suicidal ideation. Levetiracetam initially helped but symptoms worsened after cannabis relapse; restarting Levetiracetam with abstinence led to good functional recovery, though visual snow persisted mildly.