Stable quantitative EEG difference in post-LSD visual disorder by split-half analysis: evidence for disinhibition

• Published in: Psychiatry research Vol. 67; no. 3; pp. 173 - 187
• Main Authors: Abraham, Henry David, Duffy, Frank Hopkins
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 07-10-1996; Elsevier
• Subjects: Addictive behaviors; Adolescent; Adult; Adult and adolescent clinical studies; Biological and medical sciences; Brain - drug effects; Brain Mapping; Drug addiction; Electroencephalographic brain mapping; Electroencephalography; Evoked potentials; Evoked Potentials, Visual; Female; Hallucinations - etiology; Hallucinogen persisting perceptual disorder; Hallucinogens - adverse effects; Hallucinogens - pharmacology; Humans; Lysergic Acid Diethylamide - adverse effects; Lysergic Acid Diethylamide - pharmacology; Male; Medical sciences; Middle Aged; Perceptual Disorders - etiology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Evoked potentials; Hallucinogen persisting perceptual disorder; Electroencephalographic brain mapping; Consumption; Human; Perceptual disorder; Hallucination; Vision disorder; Central nervous system; Electroencephalography; Lysergide; Electrodiagnosis; Eye disease; Visual stimulus; Acoustic stimulus; Hallucinogen; Complication; Event evoked potential; Quantitative analysis; Brain (vertebrata)
• ISSN: 0925-4927; 0165-1781; 1872-7506; 1872-7123
• DOI: 10.1016/0925-4927(96)02833-8

Hallucinogen persisting perceptual disorder (HPPD) may follow the ingestion of LSD or other hallucinogens in a subset of users. It is characterized by chronic, intermittent or constant visual hallucinations of many sorts persisting beyond the period of acute drug effects. We studied 44 LSD-induced HPPD subjects and 88 matched controls to search for spectral and evoked potential differences using quantitative EEG (gEEG). HPPD subjects demonstrated faster alpha frequency and shorter VER (visual evoked response) latency, consistent with prior animal and human data on response to acute LSD administration which suggest LSD-induced cortical disinhibition. AER (auditory evoked response) latency was prolonged consistent with a differential LSD effect upon visual and auditory systems. The exploratory
T-statistic significance probability mapping (T-SPM) technique demonstrated HPPD-control differences mostly involving temporal and left parietal scalp regions, confirmed by a split-half analysis. Significant variables were all derived from the long latency flash VER and click AER. None were derived from spectral analyzed EEG data. Canonical correlation between SPM-derived measures and variables reflecting disease severity was highly significant. A between-group stepwise discriminant analysis based upon a full set of gEEG measures demonstrated 87% prospective classification success by jackknifing and 88% success in a separate split-half analysis.