Association of Hallucinogen Persisting Perception Disorder with Trait Neuroticism and Mental Health Symptoms.

Hallucinogen Persisting Perception Disorder (HPPD) may be more common than previously thought. Among 415 hallucinogen and other drug users who completed an online questionnaire, 39.7% reported symptoms of Type I HPPD and 4.3% reported symptoms of Type II HPPD. Neuroticism scores did not differ between those with and without HPPD. Individuals with Type II HPPD were more likely to report anxiety, obsessional thoughts, paranoia, hypochondria, and panic attacks, and were also more likely to have used 25I-NBOMe, dextromethorphan, nitrous oxide, and benzodiazepines. Nearly half (47.3%) had never tested their drugs, complicating attribution of HPPD severity to specific substances.

Study at a glance

Abstract

Hallucinogen Persisting Perception Disorder (HPPD) is considered rare in hallucinogen users although there are conflicting reports about its incidence and prevalence. HPPD may be more common in those with trait neuroticism. In this study, we invited hallucinogen and other drug users to complete an online questionnaire about their use of hallucinogens, their experience of HPPD symptoms, and their trait neuroticism and mental health symptoms. We received 802 responses with 415 of these containing adequate data for further analysis. 39.7% of responders reported symptoms corresponding to Type I HPPD, and 4.3% reported symptoms corresponding to Type II HPPD. We found no significant difference between neuroticism scores for participants with or without HPPD. Individuals with Type II HPPD were more likely to report mental health symptoms including anxiety, obsessional thoughts, paranoia, hypochondria and panic attacks (p < .05). We also found that individuals with Type II HPPD were more likely to report the use of 25I-NBOMe, dextromethorphan, nitrous oxide and benzodiazepines (p < .05). 47.3% of participants had never tested their drugs, making the attribution of HPPD severity to specific drugs difficult. Further work into the development of HPPD is required, particularly with the rise of hallucinogens as potential treatments for depression and other mental illnesses.