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5-MeO-DMT is a psychoactive substance found in high concentrations in the bufotoxin of the Colorado River Toad ( Bufo alvarius ). Emerging evidence suggests that vaporized 5-MeO-DMT may occasion mystical experiences of comparable intensity to those occasioned by more widely studied psychedelics such as psilocybin, but no empirical study has tested this hypothesis. Data was obtained from 20 individuals ( M age = 38.9, ± 10.7; male = 55%, Caucasian = 85%) who were administered 5-MeO-DMT as part of a psychospiritual retreat program in Mexico. All participants received 50 mg of inhaled vaporized toad bufotoxin which contains 5-MeO-DMT and completed the Mystical Experience Questionnaire (MEQ30) approximately 4-6 h after their session. Administration of 5-MeO-DMT occasioned strong mystical experiences (MEQ30 Overall M intensity = 4.17, ± 0.64, range 0-5) and the majority ( n = 15, 75%) had "a complete mystical experience" (≥60% on all MEQ30 subscales). Compared to a prior laboratory-based psilocybin study, there were no differences in the intensity of mystical effects between 5-MeO-DMT and a high dose (30 mg/70 kg) of psilocybin, but the intensity of mystical effects was significantly higher in the 5-MeO-DMT sample compared to moderate/high dose (20 mg/70 kg) of psilocybin (MEQ30 Total Score: p = 0.02, d = 0.81). Administration of vaporized 5-MeO-DMT reliably occasioned complete mystical experiences in 75% of individuals and was similar in intensity to high dose psilocybin administered in a laboratory setting. The short duration of action may be advantageous for clinical interventions and for studying mystical-type experiences.

The clock-drawing test (CDT) is widely used in clinical practice to diagnose and distinguish patients with dementia. It remains unclear, however, whether the CDT can distinguish among the early-onset dementias. Accordingly, we examined the ability of both quantitative and qualitative CDT analyses to distinguish behavioral variant frontotemporal dementia (bvFTD) and early-onset Alzheimer disease (eAD), the 2 most common neurodegenerative dementias with onset <65 years of age. We hypothesized that executive aspects of the CDT would discriminate between these 2 disorders. The study compared 15 patients with bvFTD and 16 patients with eAD on the CDT using 2 different scales and correlated the findings with neuropsychological testing and magnetic resonance imaging. The total CDT scores did not discriminate bvFTD and eAD; however, specific analysis of executive hand placement items successfully distinguished the groups, with eAD exhibiting greater errors than bvFTD. The performance on those executive hand placement items correlated with measures of naming as well as visuospatial and executive function. On tensor-based morphometry of the magnetic resonance images, executive hand placement correlated with right frontal volume. These findings suggest that lower performance on executive hand placement items occurs with involvement of the right dorsolateral frontal-parietal network for executive control in eAD, a network disproportionately affected in AD of early onset. Rather than the total performance on the clock task, the analysis of specific errors, such as executive hand placement, may be useful for early differentiation of eAD, bvFTD, and other conditions., (© The Author(s) 2015.)

Diffusion imaging and brain connectivity analyses can reveal the underlying organizational patterns of the human brain, described as complex networks of densely interlinked regions. Here, we analyzed 1.5-Tesla whole-brain diffusion-weighted images from 64 participants - 15 patients with behavioral variant frontotemporal (bvFTD) dementia, 19 with early-onset Alzheimer's disease (EOAD), and 30 healthy elderly controls. Based on whole-brain tractography, we reconstructed structural brain connectivity networks to map connections between cortical regions. We examined how bvFTD and EOAD disrupt the weighted 'rich club' - a network property where high-degree network nodes are more interconnected than expected by chance. bvFTD disrupts both the nodal and global organization of the network in both low- and high-degree regions of the brain. EOAD targets the global connectivity of the brain, mainly affecting the fiber density of high-degree (highly connected) regions that form the rich club network. These rich club analyses suggest distinct patterns of disruptions among different forms of dementia.