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
Psychosis-Relevant Effects of Intravenous Delta-9-Tetrahydrocannabinol: A Mega Analysis of Individual Participant-Data from Human Laboratory Studies
Ganesh S, Cortes-Briones J, Ranganathan M, Radhakrishnan R, Skosnik PD, D’Souza D. Psychosis-Relevant Effects of Intravenous Delta-9-Tetrahydrocannabinol: A Mega Analysis of Individual Participant-Data from Human Laboratory Studies. The International Journal Of Neuropsychopharmacology 2020, 23: 559-570. PMID: 32385508, PMCID: PMC7710917, DOI: 10.1093/ijnp/pyaa031.Peer-Reviewed Original ResearchConceptsHuman laboratory studiesHealthy human volunteersPositive symptomsTHC dosePsychotomimetic effectsHuman volunteersPsychosis-like effectsNegative Syndrome ScaleProfile of symptomsCrossover studyIntravenous administrationMotor retardationHealthy individualsSyndrome ScaleSymptomsNegative syndromeSomatic concernsSubstance useConceptual disorganizationFrequent cannabisMultiple studiesMeaningful increaseAssociation 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
2019
Effects of haloperidol on the delta-9-tetrahydrocannabinol response in humans: a responder analysis
Gupta S, De Aquino JP, D’Souza D, Ranganathan M. Effects of haloperidol on the delta-9-tetrahydrocannabinol response in humans: a responder analysis. Psychopharmacology 2019, 236: 2635-2640. PMID: 30919005, PMCID: PMC6697616, DOI: 10.1007/s00213-019-05235-x.Peer-Reviewed Original ResearchConceptsDissociative Symptoms ScalePANSS positive scalePsychotomimetic effectsHuman laboratory studiesRole of dopaminePsychosis-like effectsHaloperidol conditionNegative Syndrome ScalePANSS positive scoreDopaminergic antagonismPositive scalePlacebo conditionResponder analysisSyndrome ScaleSymptom ScaleDouble-blind studyEffects of haloperidolDopaminergic signalingOral haloperidolIndividualsOnly respondersPositive scoreIntravenous administrationHealthy individualsHaloperidol
2018
The effects of cannabidiol (CBD) on cognition and symptoms in outpatients with chronic schizophrenia a randomized placebo controlled trial
Boggs DL, Surti T, Gupta A, Gupta S, Niciu M, Pittman B, Schnakenberg Martin AM, Thurnauer H, Davies A, D’Souza D, Ranganathan M. The effects of cannabidiol (CBD) on cognition and symptoms in outpatients with chronic schizophrenia a randomized placebo controlled trial. Psychopharmacology 2018, 235: 1923-1932. PMID: 29619533, DOI: 10.1007/s00213-018-4885-9.Peer-Reviewed Original ResearchMeSH KeywordsAdministration, OralAdultAffectAntipsychotic AgentsCannabidiolChronic DiseaseCognitionCognitive DysfunctionDouble-Blind MethodFemaleFollow-Up StudiesHumansMaleMental Status and Dementia TestsMiddle AgedOutpatientsPsychiatric Status Rating ScalesSchizophreniaSchizophrenic PsychologyTreatment OutcomeConceptsMATRICS Consensus Cognitive BatterySide effectsChronic schizophreniaAntipsychotic-treated patientsMovement side effectsFixed-dose studyPlacebo-treated subjectsWeeks of treatmentPANSS total scoreEffects of cannabidiolWorsening of moodNegative Syndrome ScaleAntipsychotic-treated outpatients× time effect× time interactionMCCB composite scoreOral cannabidiolCBD groupClinical trialsParallel groupPANSS scoresMethodsThis studyPsychotic symptomsConsensus Cognitive BatterySyndrome Scale
2017
Attenuation of ketamine-induced impairment in verbal learning and memory in healthy volunteers by the AMPA receptor potentiator PF-04958242
Ranganathan M, DeMartinis N, Huguenel B, Gaudreault F, Bednar MM, Shaffer CL, Gupta S, Cahill J, Sherif MA, Mancuso J, Zumpano L, D’Souza D. Attenuation of ketamine-induced impairment in verbal learning and memory in healthy volunteers by the AMPA receptor potentiator PF-04958242. Molecular Psychiatry 2017, 22: 1633-1640. PMID: 28242871, DOI: 10.1038/mp.2017.6.Peer-Reviewed Original ResearchConceptsKetamine-induced impairmentVerbal learningAMPAR potentiatorsHopkins Verbal Learning TestN-methyl-D-aspartate receptorsVerbal Learning TestDissociative Symptoms ScaleKetamine-induced deficitsPsychotomimetic effectsMemory taskImmediate recallLearning TestCogState batteryMemory deficitsNegative Syndrome ScaleTreatment periodCognitive symptomsNMDAR functioningNMDAR antagonist ketamineNonhuman primatesNegative symptomsCognitive impairmentMemoryIsoxazolepropionic acid (AMPA) receptorsPathophysiology of schizophrenia
2015
Δ9-THC Disrupts Gamma (γ)-Band Neural Oscillations in Humans
Cortes-Briones J, Skosnik PD, Mathalon D, Cahill J, Pittman B, Williams A, Sewell RA, Ranganathan M, Roach B, Ford J, D'Souza DC. Δ9-THC Disrupts Gamma (γ)-Band Neural Oscillations in Humans. Neuropsychopharmacology 2015, 40: 2124-2134. PMID: 25709097, PMCID: PMC4613601, DOI: 10.1038/npp.2015.53.Peer-Reviewed Original ResearchConceptsAuditory steady-state responseΔ9-THCHz stimulationIntertrial coherenceDose-related effectsNeural oscillationsNegative Syndrome ScalePsychophysiological alterationsAcute effectsPsychotic disordersAnimal studiesSyndrome ScalePANSS subscalesRecent usersBehavioral effectsTotal scoreEvoked powerCannabinoidsCounterbalanced designTrend levelΓ oscillationsTest dayBand oscillationsHz conditionStimulation
2014
Effects of Nicotine on the Neurophysiological and Behavioral Effects of Ketamine in Humans
Mathalon DH, Ahn KH, Perry EB, Cho HS, Roach BJ, Blais RK, Bhakta S, Ranganathan M, Ford JM, D’Souza D. Effects of Nicotine on the Neurophysiological and Behavioral Effects of Ketamine in Humans. Frontiers In Psychiatry 2014, 5: 3. PMID: 24478731, PMCID: PMC3900858, DOI: 10.3389/fpsyt.2014.00003.Peer-Reviewed Original ResearchAuditory event-related brain potentialsEvent-related brain potentialsTest sessionsBehavioral effectsAmplitude of P3aDissociative Symptoms ScaleNicotinic acetylcholine receptor stimulationBrain potentialsP3b amplitudeMMN amplitudeP3a amplitudeNovel stimuliNeurophysiological measuresNMDA receptor hypofunctionN-methyl-D-aspartate (NMDA) receptor hypofunctionNegative Syndrome ScaleEffects of nicotineReceptor hypofunctionNeurocognitive impairmentCounterbalanced mannerP3aSchizophrenia-like effectsSyndrome ScaleInjections of nicotineInteraction of ketamine
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 signsArmodafinil as adjunctive therapy in adults with cognitive deficits associated with schizophrenia: a 4-week, double-blind, placebo-controlled study.
Kane JM, D'Souza DC, Patkar AA, Youakim JM, Tiller JM, Yang R, Keefe RS. Armodafinil as adjunctive therapy in adults with cognitive deficits associated with schizophrenia: a 4-week, double-blind, placebo-controlled study. The Journal Of Clinical Psychiatry 2010, 71: 1475-81. PMID: 20816042, DOI: 10.4088/jcp.09m05950gry.Peer-Reviewed Original ResearchMeSH KeywordsAdultAntipsychotic AgentsBenzhydryl CompoundsBenzodiazepinesCentral Nervous System StimulantsCognition DisordersDouble-Blind MethodDrug Therapy, CombinationFemaleHumansIsoxazolesMaleMiddle AgedModafinilOlanzapinePaliperidone PalmitatePsychiatric Status Rating ScalesPyrimidinesRisperidoneSchizophreniaTreatment OutcomeConceptsAdjunctive armodafinilAdjunctive therapyFinal visitNegative symptomsTotal scoreIsomer of modafinilTolerability of armodafinilPlacebo-controlled studyPrimary efficacy measureSecondary outcome measuresPANSS total scoreSANS total scoreNegative symptom scoresNegative Syndrome ScaleDaily placeboStable dosesAdverse eventsOral risperidoneSymptom scoresEfficacy measuresSchizophrenia (MATRICS) Consensus Cognitive BatteryOutcome measuresStable schizophreniaSD changeArmodafinil
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