OPEN Foundation

Day: 1 June 2018

Pharmacological fMRI: Effects of subanesthetic ketamine on resting-state functional connectivity in the default mode network, salience network, dorsal attention network and executive control network.

Abstract

BACKGROUND:
Subanesthetic dosages of the NMDAR antagonist, S-Ketamine, can cause changes in behavior in healthy subjects, which are similar to the state acute psychosis and are relevant in translational schizophrenia research. Functional magnetic resonance imaging (fMRI) can be used for non-hypothesis-driven analysis of brain connectivity. The correlation between clinical behavioral scores and neuroimaging can help to characterize ketamine effects on healthy brains in resting state.
METHOD:
seventeen healthy, male subjects (mean: 27.42 years, SD: 4.42) were administered an infusion with S-Ketamine (initial bolus 1 mg/kg and continuous infusion of 0.015625 mg/kg/min with dosage reduction -10%/10 min) or saline in a randomized, double-blind, cross-over study. During infusion, resting state connectivity was measured and analyzed with a seed-to-voxel fMRI analysis approach. The seed regions were located in the posterior cingulate cortex, intraparietal sulcus, dorsolateral prefrontal cortex and fronto-insular cortex. Receiver operating characteristics (ROC) were calculated to assess the accuracy of the ketamine-induced functional connectivity changes. Bivariate Pearson correlation was used for correlation testing of functional connectivity changes with changes of clinical scores (PANSS, 5D-ASC).
RESULTS:
In the executive network (ECN), ketamine significantly increases the functional connectivity with parts of the anterior cingulum and superior frontal gyrus, but no significant correlations with clinical symptoms were found. Decreased connectivity between the salience network (SN) and the calcarine fissure was found, which is significantly correlated with negative symptoms (PANSS) (R2 > 0.4).
CONCLUSION:
Decreased ketamine-induced functional connectivity in the salience network may qualify as accurate and highly predictive biomarkers for ketamine induced negative symptoms.
Mueller, F., Musso, F., London, M., de Boer, P., Zacharias, N., & Winterer, G. (2018). Pharmacological fMRI: Effects of subanesthetic ketamine on resting-state functional connectivity in the default mode network, salience network, dorsal attention network and executive control network. NeuroImage: Clinical., 10.1016/j.nicl.2018.05.037
Link to full text

A Survey of American Psychiatrists' Attitudes Toward Classic Hallucinogens

Abstract

Recent years have seen renewed interest and research about the use of hallucinogens as possible agents in the treatment of psychiatric disorders. However, we are unaware of studies assessing the current attitudes of American psychiatrists regarding hallucinogens. Therefore, we e-mailed surveys to 1000 members of the American Psychiatric Association-250 resident-fellows and 750 attending psychiatrists. The response rate was 32.4%. Respondents tended to perceive hallucinogens as potentially hazardous and appropriately illegal for recreational purposes. However, a large minority expressed optimism about the potential use of hallucinogens for psychiatric treatment. Male and trainee respondents, as compared with female and attending respondents, reported less concern about the risks of hallucinogens and greater optimism about their therapeutic potential. Younger psychiatrists also seemed more optimistic. Optimism among trainees and younger psychiatrists may possibly reflect greater exposure to recent positive publications about hallucinogens and less awareness of more negative past reports.
Barnett, B. S., Siu, W. O., & Pope Jr, H. G. (2018). A Survey of American Psychiatrists’ Attitudes Toward Classic Hallucinogens. The Journal of nervous and mental disease206(6), 476-480. 10.1097/NMD.0000000000000828
Link to full text

A Survey of American Psychiatrists’ Attitudes Toward Classic Hallucinogens

Abstract

Recent years have seen renewed interest and research about the use of hallucinogens as possible agents in the treatment of psychiatric disorders. However, we are unaware of studies assessing the current attitudes of American psychiatrists regarding hallucinogens. Therefore, we e-mailed surveys to 1000 members of the American Psychiatric Association-250 resident-fellows and 750 attending psychiatrists. The response rate was 32.4%. Respondents tended to perceive hallucinogens as potentially hazardous and appropriately illegal for recreational purposes. However, a large minority expressed optimism about the potential use of hallucinogens for psychiatric treatment. Male and trainee respondents, as compared with female and attending respondents, reported less concern about the risks of hallucinogens and greater optimism about their therapeutic potential. Younger psychiatrists also seemed more optimistic. Optimism among trainees and younger psychiatrists may possibly reflect greater exposure to recent positive publications about hallucinogens and less awareness of more negative past reports.
Barnett, B. S., Siu, W. O., & Pope Jr, H. G. (2018). A Survey of American Psychiatrists’ Attitudes Toward Classic Hallucinogens. The Journal of nervous and mental disease206(6), 476-480. 10.1097/NMD.0000000000000828
Link to full text

27 June - Spiritual & Existential Dimensions in Psychedelic Care: Challenges & Insights

X