Measuring acute effects of subanesthetic ketamine on cerebrovascular hemodynamics in humans using TD-fNIRS.

Quantifying neural activity in natural conditions (i.e. conditions comparable to the standard clinical patient experience) during the administration of psychedelics may further our scientific understanding of the effects and mechanisms of action. This data may facilitate the discovery of novel biomarkers enabling more personalized treatments and improved patient outcomes. In this single-blind, placebo-controlled study with a non-randomized design, we use time-domain functional near-infrared spectroscopy (TD-fNIRS) to measure acute brain dynamics after intramuscular subanesthetic ketamine (0.75 mg/kg) and placebo (saline) administration in healthy participants (n = 15, 8 females, 7 males, age 32.4 ± 7.5 years) in a clinical setting. We found that the ketamine administration caused an altered state of consciousness and changes in systemic physiology (e.g. increase in pulse rate and electrodermal activity). Furthermore, ketamine led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations, and a decrease in the global brain connectivity of the prefrontal region. Lastly, we provide preliminary evidence that a combination of neural and physiological metrics may serve as predictors of subjective mystical experiences and reductions in depressive symptomatology. Overall, our study demonstrated the successful application of fNIRS neuroimaging to study the physiological effects of the psychoactive substance ketamine in humans, and can be regarded as an important step toward larger scale clinical fNIRS studies that can quantify the impact of psychedelics on the brain in standard clinical settings.

Mania following use of ibogaine: A case series.

BACKGROUND: Ibogaine is a naturally occurring hallucinogen with postulated anti-addictive qualities. While illegal domestically, a growing number of individuals have sought it out for treatment of opiate dependence, primarily in poorly regulated overseas clinics. Existing serious adverse events include cardiac and vestibular toxicity, though ours is the first report of mania stemming from its use. OBJECTIVES: To report on a case series of psychiatric emergency room patients whose unregulated use of ibogaine resulted in mania in three patients with no prior diagnosis of bipolar illness. METHODS: Review and summarize charts of three cases. Relevant literature was also reviewed for discussion. RESULTS: Two cases of reported ibogaine ingestion for self-treatment of addictions, and one for psycho-spiritual experimentation resulted in symptoms consistent with mania. No prior reports of mania were found in the literature, and the literature suggests growing popularity of ibogaine's use. CONCLUSIONS: The three cases presented demonstrate a temporal association between ibogaine ingestion and subsequent development of mania. SCIENTIFIC SIGNIFICANCE: In light of these cases, clinicians faced with a new onset mania may benefit from careful substance use and treatment history, specifically regarding opiates. In the vulnerable and often desperate addiction population, in particular, the number of patients seeking this treatment appears to be growing. We advise clinicians to be prepared for discussing the safety, efficacy, and paucity of good data regarding ibogaine with patients who may be considering its use. (Am J Addict 2015;24:203-205).