Neuropsychopharmacology Reports
February 21, 2021
Tomoyuki Nakamura, Masaru Tomita, N. Horikawa et al.
29 citations
About one-third of patients with major depressive disorder have treatment-resistant depression. Of those, one-third do not respond to ketamine, a newer antidepressant. Resting-state functional MRI was tested for its ability to predict which patients with treatment-resistant depression would respond to ketamine treatment.
Neuropsychopharmacology Reports
March 13, 2024
Kengo Yonezawa, Hideaki Tani, Shinichiro Nakajima et al.
5 citations
A Japanese version of the Mystical Experiences Questionnaire (MEQ30) has been developed to assess mystical experiences induced by psychedelics, which are being studied as potential treatments for mental illness. Two Japanese psychiatrists independently translated the original English questionnaire into Japanese, then reconciled the translations into a unified version. This version was back-translated into English and reviewed by the original authors through an iterative process until they approved the final back-translated version. The authorized Japanese MEQ30 is now available for use in psychedelic-assisted therapy research with Japanese speakers, though further studies are needed to evaluate its reliability and validity.
Neuropsychopharmacology Reports
July 20, 2025
Zofia Kachlik, Wiesław Jerzy Cubała, Michał Walaszek et al.
3 citations
Ketamine is a fast-acting antidepressant for treatment-resistant bipolar depression, but about 40% of patients do not respond. Among 35 patients receiving a four-week ketamine regimen, nonresponders had more psychiatric comorbidities (median 2 vs. 1) and were more likely to have any psychiatric comorbidity (78.6% vs. 33.3%) and prior benzodiazepine use (64.3% vs. 23.8%). Individual comorbidities and baseline suicidality were not linked to response. Ketamine remains safe and well-tolerated for short-term use, but a heavier comorbidity burden and benzodiazepine use may predict nonresponse.
Neuropsychopharmacology Reports
February 6, 2021
Yoko Hagino, F. Scott Hall, George R. Uhl et al.
3 citations
The hallucinogenic tryptamine analogue 5-MeO-DIPT decreases extracellular serotonin in the striatum but not in the prefrontal cortex of mice. In mice lacking the serotonin transporter, 5-MeO-DIPT does not affect serotonin levels, indicating its action depends on that transporter. When a 5-HT1A receptor antagonist is present, 5-MeO-DIPT substantially increases serotonin, suggesting the drug's serotonin reuptake inhibition is masked by its concurrent activation of 5-HT1A receptors. 5-MeO-DIPT also dose-dependently increases extracellular dopamine in the prefrontal cortex regardless of serotonin transporter presence, an effect not blocked by the 5-HT1A antagonist. Thus, 5-MeO-DIPT dually acts on the serotonin transporter and 5-HT1A receptors, limiting serotonin elevation while independently raising dopamine in the prefrontal cortex.
Neuropsychopharmacology Reports
March 13, 2024
Keisuke Kusudo, Hideaki Tani, Kengo Yonezawa et al.
2 citations
A Japanese version of the Ego-Dissolution Inventory (EDI) was developed through a translation and back-translation process following international guidelines. Two Japanese psychiatrists independently translated the original English EDI, reconciled differences, and had the resulting version back-translated into English. The original authors reviewed and approved the back-translated version after iterative revisions. The final Japanese EDI is intended to help assess ego-dissolution experiences during psychedelic-assisted therapy in Japanese-speaking populations. Further research is needed to test the reliability and validity of this new instrument.
Neuropsychopharmacology Reports
November 23, 2025
Hideaki Kato, Yoshimi Ichimaru, Masaaki Kurihara et al.
1 citation
A simple behavioral test in mice may help regulators quickly identify new hallucinogenic drugs. Mice given the hallucinogen-like compound DOI showed aversive effects in a conditioned place aversion test and abnormal behavior in a marble-burying test. These responses likely stem from the drug's hallucinogenic properties. The findings suggest that such rodent tests could serve as a rapid, accurate screening method for designating new psychoactive substances as controlled drugs, aiding prevention of drug abuse.
Neuropsychopharmacology Reports
November 8, 2024
Hideaki Tani, Kengo Yonezawa, Keisuke Kusudo et al.
1 citation
A Japanese version of the Challenging Experience Questionnaire (CEQ) was developed to assess difficult aspects of psychedelic experiences in Japanese speakers. Following international guidelines for translation and cultural adaptation, two psychiatrists independently translated the original English CEQ into Japanese, reconciled the versions, and had them back-translated into English. The original authors reviewed the back-translation and approved the final version after revisions. The resulting questionnaire enables evaluation of challenging experiences during psychedelic-assisted therapy for Japanese-speaking populations, though further studies are needed to confirm its reliability and validity.