Drug Testing and Analysis
June 26, 2012
Torsten Passie, H. M. Emrich, Matthias Karst et al.
114 citations
A 19-year-old male with severe PTSD symptoms, including flashbacks, panic attacks, and self-mutilation, experienced dramatic symptom reduction after smoking cannabis resin. This review examines clinical and preclinical neurobiological evidence for cannabis's effects on PTSD. Cannabis may reduce the strength and emotional impact of traumatic memories through synergistic mechanisms, potentially aiding sleep, reducing anxiety, and lessening flashback involvement. Endocannabinoid signaling systems in stress-sensitive brain regions like the hypothalamus and amygdala suggest their role in regulating stress responses. Evidence increasingly indicates cannabinoids may play a role in fear extinction and have antidepressive effects. Further studies are needed to evaluate cannabinoids' therapeutic potential in PTSD.
Cephalalgia
March 26, 2010
Matthias Karst, John H. Halpern, Michael Bernateck et al.
104 citations
Cluster headache is a severe, one-sided headache condition affecting 0.1% of people. Standard treatments like oxygen and sumatriptan can fail, and surgical options carry serious risks. An internet survey of 53 patients suggested that the hallucinogens psilocybin and LSD may abort attacks and extend remission better than standard drugs, but these substances are criminalized. To test whether a non-hallucinogenic LSD analog could also help, researchers investigated 2-bromo-LSD (BOL-148). Past studies found BOL-148 non-toxic and non-hallucinogenic, with only mild side effects at the dose used, and no long-term effects in over 300 healthy subjects or in schizophrenic women given 30mg daily for weeks.
Neuropsychobiology
January 1, 2005
Torsten Passie, Matthias Karst, Birgitt Wiese et al.
35 citations
The first neuropsychological study of the S-enantiomer of ketamine, a noncompetitive NMDA antagonist, found that low and high subanaesthetic doses produced only nonsignificant impairment on most cognitive tasks in 12 healthy male volunteers. However, tasks involving divided and sustained attention, along with objective and subjective psychopathology scores, showed significant impairment that increased with dose. These results suggest that ketamine's effects on attention may model aspects of schizophrenia.
Journal of Psychopharmacology
January 1, 2003
Torsten Passie, Matthias Karst, Mathias Borsutzky et al.
27 citations
The NMDA neurotransmitter system's role in psychoses is not fully understood, but NMDA antagonists like phencyclidine and ketamine induce psychotic states similar to schizophrenia. Binocular depth inversion, a visual illusion impaired in psychotic states, was tested in 12 healthy male volunteers using stereoscopic pictures of natural and artificial objects. Two subanaesthetic doses of the psychotomimetic S-enantiomer of ketamine were compared with placebo. Despite dose-dependent subjective and objective psychopathology, no significant impairment of binocular depth perception occurred with (S)-ketamine. The findings suggest implications for memory, perception formation, and bottom-up processing in ketamine model psychosis and schizophrenia.