Hallucinogen persisting perception disorder (HPPD) is described through diagnostic criteria, clinical presentations, types, and treatment approaches. Three case reports illustrate different types: a 23-year-old with prior cannabis use developed HPPD type I after taking psilocybin mushrooms with alcohol and hash, with symptoms recurring after cannabis but not alcohol, and reducing within a year. Two other cases of HPPD type II occurred after ecstasy use, which is not typically considered a hallucinogen; the condition was stressful and frightening, and treatment with tofisopam, lamotrigine, and sertraline smoothed but did not eliminate visual impairments. Scientific sources suggest HPPD may affect more than 50% of hallucinogen users and is often underdiagnosed.
Cannabis remains the most widely used drug globally, with two recent trends: liberalization of cannabis laws in some countries and increased tetrahydrocannabinol content in the plant. This narrative review, aimed at Russian addiction specialists, examines the understudied link between cannabis use and psychotic disorders. It covers topics such as the causal relationship between cannabis and psychosis, gender differences, genetic predisposition, adolescent use, reasons for use, suicidal behavior, co-use with tobacco, and clinical treatment. The review highlights a lack of domestic Russian research on these issues, providing a general overview of the current state of knowledge.