2022
Sublingual Dexmedetomidine for the Treatment of Acute Agitation in Adults With Schizophrenia or Schizoaffective Disorder: A Randomized Placebo-Controlled Trial.
Citrome L, Preskorn SH, Lauriello J, Krystal JH, Kakar R, Finman J, De Vivo M, Yocca FD, Risinger R, Rajachandran L. Sublingual Dexmedetomidine for the Treatment of Acute Agitation in Adults With Schizophrenia or Schizoaffective Disorder: A Randomized Placebo-Controlled Trial. The Journal Of Clinical Psychiatry 2022, 83 PMID: 36198061, DOI: 10.4088/jcp.22m14447.Peer-Reviewed Original ResearchConceptsAcute agitationHours postdoseSchizoaffective disorderTotal scorePrimary efficacy endpointPlacebo-controlled studyAdrenergic receptor agonistFifth Edition criteriaNegative Syndrome ScaleDexmedetomidine groupOral hypoesthesiaStudy medicationDry mouthEfficacy endpointOrthostatic hypotensionRandomized PlaceboAdverse eventsReceptor agonistEdition criteriaDexmedetomidineMean changePEC scoresPlaceboSyndrome ScaleUS sites
2021
The effect of ketamine on psychopathology and implications for understanding schizophrenia and its therapeutic use: a meta-analysis
Beck K, Hindley G, Borgan F, Ginestet C, McCutcheon R, Brugger S, Driesen N, Ranganathan M, D'Souza D, Taylor M, Krystal J, Howes O. The effect of ketamine on psychopathology and implications for understanding schizophrenia and its therapeutic use: a meta-analysis. BJPsych Open 2021, 7: s237-s237. PMCID: PMC8771247, DOI: 10.1192/bjo.2021.634.Peer-Reviewed Original ResearchBrief Psychiatric Rating ScaleEffects of ketaminePlacebo conditionPositive symptomsKetamine administrationKetamine effectsHealthy participantsHealthy volunteersNegative symptomsTherapeutic useAcute ketamine administrationAcute ketamine challengeMagnitude of symptomsStudy-level dataSub-group analysisPsychiatric Rating ScaleSchizophrenia-like symptomatologySchizophrenia-like symptomsMean change scoresNegative Syndrome ScalePositive psychotic symptomsSignificant increaseEffect sizeBolus dosesKetamine challenge
2020
Association of Ketamine With Psychiatric Symptoms and Implications for Its Therapeutic Use and for Understanding Schizophrenia
Beck K, Hindley G, Borgan F, Ginestet C, McCutcheon R, Brugger S, Driesen N, Ranganathan M, D’Souza D, Taylor M, Krystal JH, Howes OD. Association of Ketamine With Psychiatric Symptoms and Implications for Its Therapeutic Use and for Understanding Schizophrenia. JAMA Network Open 2020, 3: e204693. PMID: 32437573, PMCID: PMC7243091, DOI: 10.1001/jamanetworkopen.2020.4693.Peer-Reviewed Original ResearchConceptsBrief Psychiatric Rating ScalePlacebo conditionPositive symptomsNegative symptomsHealthy participantsMean differenceKetamine administrationPANSS scoresHealthy volunteersPsychotomimetic symptomsTherapeutic useAcute ketamine administrationAcute ketamine challengePlacebo-controlled studyEffect sizeMagnitude of symptomsStudy-level dataPsychiatric Rating ScaleMeta-Analyses (PRISMA) guidelinesPreferred Reporting ItemsAssociation of ketamineNegative Syndrome ScaleSignificant increaseAcute administrationBolus doses
2018
Similar psychotic and cognitive profile between ketamine dependence with persistent psychosis and schizophrenia
Cheng WJ, Chen CH, Chen CK, Huang MC, Pietrzak RH, Krystal JH, Xu K. Similar psychotic and cognitive profile between ketamine dependence with persistent psychosis and schizophrenia. Schizophrenia Research 2018, 199: 313-318. PMID: 29510925, DOI: 10.1016/j.schres.2018.02.049.Peer-Reviewed Original ResearchConceptsSZ patientsCognitive impairmentCognitive functionSocial-emotional cognitionCogstate Brief BatteryPsychomotor processing speedTreatment-seeking patientsSpatial problemsSymptom profilesSevere symptom profileVerbal memoryCognitive profileKetamine-dependent patientsVisual learningBrief batteryProcessing speedNegative Syndrome ScaleBiology of psychosisKetamine usersCognitive dysfunctionPersistent psychosisMemorySubscale scoresKetamine abuseMinority of users
2014
Preliminary analysis of positive and negative syndrome scale in ketamine-associated psychosis in comparison with schizophrenia
Xu K, Krystal JH, Ning Y, Chen da C, He H, Wang D, Ke X, Zhang X, Ding Y, Liu Y, Gueorguieva R, Wang Z, Limoncelli D, Pietrzak RH, Petrakis IL, Zhang X, Fan N. Preliminary analysis of positive and negative syndrome scale in ketamine-associated psychosis in comparison with schizophrenia. Journal Of Psychiatric Research 2014, 61: 64-72. PMID: 25560772, PMCID: PMC4445679, DOI: 10.1016/j.jpsychires.2014.12.012.Peer-Reviewed Original ResearchConceptsKetamine groupNegative Syndrome ScaleSchizophrenia groupSyndrome ScaleN-methyl-D-aspartate (NMDA) glutamate receptor antagonistGlutamate receptor antagonistsPotential confounding factorsEarly course schizophreniaSymptom dimensionsSymptoms of schizophreniaReceptor antagonistChronic schizophreniaHealthy subjectsKetamine abuseSchizophrenia psychosisSchizophrenia patientsConfounding factorsSymptom severitySymptomsInpatientsSchizophreniaPsychosisKetamine usersDissociation symptomsPrincipal component factor analysisSymptom structure and severity: A comparison of responses to the positive and negative syndrome scale (PANSS) between patients with PTSD or schizophrenia
Stefanovics EA, Krystal JH, Rosenheck RA. Symptom structure and severity: A comparison of responses to the positive and negative syndrome scale (PANSS) between patients with PTSD or schizophrenia. Comprehensive Psychiatry 2014, 55: 887-895. PMID: 24602497, DOI: 10.1016/j.comppsych.2014.01.014.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAged, 80 and overAntipsychotic AgentsChronic DiseaseCombat DisordersDiagnosis, DifferentialDouble-Blind MethodFemaleHumansMaleMiddle AgedPsychiatric Status Rating ScalesPsychometricsRisperidoneSchizophreniaSchizophrenic PsychologyStress Disorders, Post-TraumaticVeteransYoung AdultConceptsPost-traumatic stress disorderNegative Syndrome ScaleSyndrome ScalePTSD samplePlacebo-controlled trialPsychosis-related factorsClinical trial patientsClinical Antipsychotic TrialsT-testSchizophrenia sampleExploratory factor analysisSymptoms of schizophreniaMilitary-related post-traumatic stress disorderSymptom structureAdjunctive risperidoneTrial patientsTraumatic Stress DisorderAntipsychotic TrialsSecondary data analysisSevere symptomsIndependent factorsDepressive factorsPatientsSymptom ratingsStress disorder
2013
Relationship of resting brain hyperconnectivity and schizophrenia-like symptoms produced by the NMDA receptor antagonist ketamine in humans
Driesen NR, McCarthy G, Bhagwagar Z, Bloch M, Calhoun V, D'Souza DC, Gueorguieva R, He G, Ramachandran R, Suckow RF, Anticevic A, Morgan PT, Krystal JH. Relationship of resting brain hyperconnectivity and schizophrenia-like symptoms produced by the NMDA receptor antagonist ketamine in humans. Molecular Psychiatry 2013, 18: 1199-1204. PMID: 23337947, PMCID: PMC3646075, DOI: 10.1038/mp.2012.194.Peer-Reviewed Original ResearchConceptsFunctional connectivityNegative symptomsGamma-aminobutyric acid (GABA) neuronsNMDA receptor antagonist ketamineAspartate glutamate receptor antagonistContinuous ketamine infusionGlutamate receptor antagonistsNMDA-R antagonistsCortical functional connectivityNMDA-R antagonist ketamineSchizophrenia-like symptomsHealthy human subjectsNegative Syndrome ScaleBrain functional connectivityPrimary samplesRegion-specific mannerFunctional magnetic resonanceKetamine infusionReceptor antagonistPathological increaseSyndrome ScaleSymptomsPreclinical researchKetamineBrain oscillations
2010
Clinical significance of neurological soft signs in schizophrenia: Factor analysis of the Neurological Evaluation Scale
Sewell RA, Perry EB, Karper LP, Bell MD, Lysaker P, Goulet JL, Brenner L, Erdos J, d'Souza DC, Seibyl JP, Krystal JH. Clinical significance of neurological soft signs in schizophrenia: Factor analysis of the Neurological Evaluation Scale. Schizophrenia Research 2010, 124: 1-12. PMID: 20855185, DOI: 10.1016/j.schres.2010.08.036.Peer-Reviewed Original ResearchConceptsNeurological Evaluation ScaleAbnormal Involuntary Movement ScaleDigit Symbol Substitution TaskWisconsin Card Sorting TestNeurologic deficitsClinical significanceExtrapyramidal Symptom Rating ScaleMore extrapyramidal symptomsBarnes Akathisia ScaleDetailed clinical assessmentNeurological soft signsSymptom Rating ScaleNegative Syndrome ScaleHigher AIMS scoresEvaluation ScaleNeurological deficitsExtrapyramidal symptomsClinical correlatesDeficit syndrome schizophreniaClinical evaluationClinical assessmentAIMS scoresLower PANSSMovement ScaleSoft signs
2006
Potentiation of Low Dose Ketamine Effects by Naltrexone: Potential Implications for the Pharmacotherapy of Alcoholism
Krystal JH, Madonick S, Perry E, Gueorguieva R, Brush L, Wray Y, Belger A, D'Souza DC. Potentiation of Low Dose Ketamine Effects by Naltrexone: Potential Implications for the Pharmacotherapy of Alcoholism. Neuropsychopharmacology 2006, 31: 1793-1800. PMID: 16395307, DOI: 10.1038/sj.npp.1300994.Peer-Reviewed Original ResearchConceptsNMDA glutamate receptorsNMDA receptor antagonismKetamine doseReceptor antagonismGlutamate receptorsKetamine effectsProtective effectPlacebo-controlled human laboratory studyOpiate receptor antagonismEfficacy of naltrexoneDose-related fashionNMDA receptor antagonist effectsReceptor antagonist effectsTotal PANSS scoreHuman laboratory studiesPharmacotherapy of alcoholismTreatment of alcoholismHealthy human subjectsHigher ketamine doseNegative Syndrome ScaleLower ketamine doseSignificant behavioral effectsSubanesthetic dosePANSS scoresEthanol drink