["Flashback": spontaneous psychotic episodes in adolescence resulting from psychedelic drug use]

A Review of Hallucinogen Persisting Perception Disorder (HPPD) and an Exploratory Study of Subjects Claiming Symptoms of HPPD

Hallucinogen persisting perception disorder (HPPD) is rarely encountered in clinical settings. It is described as a re-experiencing of some perceptual distortions induced while intoxicated and suggested to subsequently cause functional impairment or anxiety. Two forms exist: Type 1, which are brief "flashbacks," and Type 2 claimed to be chronic, waxing, and waning over months to years. A review of HPPD is presented. In addition, data from a comprehensive survey of 20 subjects reporting Type-2 HPPD-like symptoms are presented and evaluated. Dissociative Symptoms are consistently associated with HPPD. Results of the survey suggest that HPPD is in most cases due to a subtle over-activation of predominantly neural visual pathways that worsens anxiety after ingestion of arousal-altering drugs, including non-hallucinogenic substances. Individual or family histories of anxiety and pre-drug use complaints of tinnitus, eye floaters, and concentration problems may predict vulnerability for HPPD. Future research should take a broader outlook as many perceptual symptoms reported were not first experienced while intoxicated and are partially associated with pre-existing psychiatric comorbidity.

Short and Long Term Adverse Reactions in Young Drug Abusers

A total of 100 young drug abusers registered in a treatment program were examined clinically during therapy and personally followed-up 3 and 6 years later. At the time of first contact, 69% had previously experienced flashbacks. It was found that not only users of psychedelic drugs, but also users of ephedrine, organic solvents and antihistaminic drugs reported “bad trip” experiences and flashbacks. Few physical adverse reactions were observed. At the end of the period, 40% of the males and 21% of the females still were bothered by flashbacks, but none of these had shown signs of a lasting psychotic symptomatology.

Clinical examination revealed no lasting physical damage due to the abuse of drugs. Up to the time of last follow-up, 4 persons, all males, had died.

Flashbacks: a personal follow-up

During the period 1971-1973, it was found that 53 out of 91 young drug abusers in a psychiatric hospital had experienced flashbacks. This applied to as many as 50 out of the 65 patients who had used LSD, but also to abusers of organic solvents and cannabis. As many as 38% of the patients were found to be severely incapacitated by their flashbacks. On a personal follow-up 1 1/2-4 years after the first therapeutic contact, 35 patients were still troubled by flashbacks. On the whole reactions were less intense than at the time of the first contact. No relation between the flashbacks and protracted psychotic development could be established. The overall clinical and social course was worse for patients with flashbacks than for the rest of the population. Patients still bothered by flashbacks used drugs and alcohol as sedatives to a greater extent than the rest.