Adverse effect of other psychodysleptics, subs encntr

This code signifies a patient experiencing an unintended and harmful reaction to a hallucinogenic substance, such as LSD, psilocybin, or MDMA, during a follow-up visit. The adverse effect could manifest as psychiatric symptoms (e.g., psychosis, severe anxiety, flashbacks) or physiological disturbances. This code is used when the initial treatment for the adverse effect has already occurred.

Apply this code for patients presenting for ongoing management or evaluation of an adverse effect from a hallucinogen after their initial presentation and treatment. Examples include a patient returning for psychiatric follow-up after an acute hallucinogen-induced psychosis, or for continued monitoring of persistent perceptual disturbances (HPPD) following a "bad trip." It indicates that the patient is no longer in the acute phase of the adverse reaction.

• Always use in conjunction with codes for the specific manifestations of the adverse effect (e.g., F23 for acute psychotic disorder, F41.0 for panic disorder).
• Ensure the "D" seventh character is appropriate for a subsequent encounter; do not use for initial treatment ("A") or sequela ("S").
• Distinguish from poisoning (T40.991-) or underdosing (T40.996-) which have different clinical implications and coding guidelines.