F16.983 - Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)
F16.9 - Hallucinogen use, unspecified F16.98 - Hallucinogen use, unspecified with other specified hallucinogen-induced disorder F16.983 - Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks)