Rajiv Radhakrishnan, MBBS, MD, FAPA
Associate Professor of PsychiatryCards
About
Research
Overview
Medical Research Interests
Marijuana Abuse; Psychoses, Substance-Induced; Schizophrenia
Public Health Interests
Mental Health; Substance Use, Addiction
Publications
2025
International perspectives on physician knowledge, attitudes, and practices related to medical cannabis
Syed S, Singh J, Elkholy H, Palavra I, Tomicevic M, Eric A, da Costa M, Guloksuz S, Radhakrishnan R. International perspectives on physician knowledge, attitudes, and practices related to medical cannabis. Frontiers In Public Health 2025, 13: 1463871. PMID: 40051509, PMCID: PMC11882600, DOI: 10.3389/fpubh.2025.1463871.Peer-Reviewed Original ResearchConceptsPhysicians' knowledgeStrength of evidenceMedical cannabisCross-sectional survey of physiciansSurvey of physiciansCross-sectional surveyYears of clinical experienceNegative health outcomesCannabis useClinical experienceRefractory chronic neuropathic painClinical decision-makingHealth outcomesPhysicians' attitudesPhysicians' willingnessChronic neuropathic painMedical use of cannabisRisk of psychosisDaily cannabis useMedication useDescriptive statisticsRisk of addictionMedical indicationsUse of cannabisPhysicians
2024
Cognitive functioning and functional ability in women with schizophrenia and homelessness
Menon J, Kantipudi S, Mani A, Radhakrishnan R. Cognitive functioning and functional ability in women with schizophrenia and homelessness. Schizophrenia Research Cognition 2024, 39: 100338. PMID: 39610698, PMCID: PMC11603006, DOI: 10.1016/j.scog.2024.100338.Peer-Reviewed Original ResearchWorld Health Organization Disability Assessment ScaleFrontal Assessment BatteryCognitive functionCognitive dysfunctionScale for Assessment of Negative SymptomsAssessment of Negative SymptomsDisability Assessment ScaleStudies of schizophreniaHigher cognitive dysfunctionPremorbid level of functionCognitive function of womenNegative symptomsAssessment batteryPremorbid levelSchizophreniaCognitive AssessmentCognitive impairmentSemi-structured proformaDementia ScaleLevel of functionAssessment ScalePsychosocial factorsHigher literacy levelsGroup of womenFunctional abilityEffects of Buprenorphine, Methadone, and Substance Use on COVID-19 Morbidity and Mortality
Christian N, Zhou X, Radhakrishnan R. Effects of Buprenorphine, Methadone, and Substance Use on COVID-19 Morbidity and Mortality. Journal Of Addiction Medicine 2024, 19: 223-226. PMID: 39475125, DOI: 10.1097/adm.0000000000001386.Peer-Reviewed Original ResearchConceptsActive substance useSubstance useAssociated with increased morbidityDuration of hospitalizationCOVID-19 outcomesOpioid useSubstance use disordersImpact of substance useCOVID-19 infectionEffects of buprenorphineOpioid use disorderRetrospective cohort studyUse disorderAll-cause mortalityCOVID-19 positive patientsUrine toxicologyMultivariate logistic regressionAssociated with statistically significant increasesMedical comorbidityStatistically significant differenceMOUD treatmentStatistically significant increaseAssociated with worse COVID-19 outcomesCOVID-19 morbidityUrban hospital system11C-UCB-J PET imaging is consistent with lower synaptic density in autistic adults
Matuskey D, Yang Y, Naganawa M, Koohsari S, Toyonaga T, Gravel P, Pittman B, Torres K, Pisani L, Finn C, Cramer-Benjamin S, Herman N, Rosenthal L, Franke C, Walicki B, Esterlis I, Skosnik P, Radhakrishnan R, Wolf J, Nabulsi N, Ropchan J, Huang Y, Carson R, Naples A, McPartland J. 11C-UCB-J PET imaging is consistent with lower synaptic density in autistic adults. Molecular Psychiatry 2024, 30: 1610-1616. PMID: 39367053, DOI: 10.1038/s41380-024-02776-2.Peer-Reviewed Original ResearchPositron emission tomographySynaptic densityAutistic adultsBrain regionsAutistic featuresClinical phenotype of autismNon-autistic participantsPhenotype of autismNon-autistic individualsRelationship to clinical characteristicsSynaptic vesicle glycoprotein 2AAssociated with clinical measuresPost-mortem studiesPositron emission tomography scanPrefrontal cortexClinician ratingsAutism groupNeural basisBrain areasNeural processesBetween-group differencesVolumetric differencesBinding potentialDensity of synapsesAutismEfficacy and Safety of Ketamine/Esketamine in Bipolar Depression in a Clinical Setting.
Santucci M, Ansari M, Nikayin S, Radhakrishnan R, Rhee T, Wilkinson S. Efficacy and Safety of Ketamine/Esketamine in Bipolar Depression in a Clinical Setting. The Journal Of Clinical Psychiatry 2024, 85 PMID: 39361411, DOI: 10.4088/jcp.24m15376.Peer-Reviewed Original ResearchConceptsBipolar depressionAcute seriesRisk of affective switchDiagnosis of bipolar depressionRefractory bipolar depressionAcute phaseMADRS scoreAffective switchIntranasal esketamineManic episodesBipolar disorderCohort of patientsAttending psychiatristsSource of morbidityEsketamineSample of patientsIV ketamineMaintenance treatmentDepressionClinical responseHeightened riskClinical outcomesMania/hypomaniaKetamineKetamine/esketamineSubstance use and spine density: a systematic review and meta-analysis of preclinical studies
Oliva H, Prudente T, Nunes E, Cosgrove K, Radhakrishnan R, Potenza M, Angarita G. Substance use and spine density: a systematic review and meta-analysis of preclinical studies. Molecular Psychiatry 2024, 29: 2873-2885. PMID: 38561468, PMCID: PMC11894807, DOI: 10.1038/s41380-024-02519-3.Peer-Reviewed Original ResearchSpine densityPrefrontal cortexSubstance useDrug self-administrationHippocampal spine densityEffects of cocaineSubstance use disordersConvergence of findingsSpine density changesSubstances of abuseMeta-analysis of preclinical studiesNucleus accumbensBehavioral sensitizationSelf-administrationBrain mechanismsPreclinical studiesBrain regionsMorphine effectsSynaptic density changesMeta-analysisAmphetamineSynaptic densityCocaineModerate-to-highCortexIn Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect?
Radhakrishnan R. In Vivo Synaptic Density in Early Schizophrenia: Are There No Differences or Are They Too Small to Detect? Biological Psychiatry 2024, 95: 605-607. PMID: 38479976, DOI: 10.1016/j.biopsych.2024.01.016.Peer-Reviewed Original ResearchConceptsSynaptic densityA systematic review of approaches to improve medication adherence in homeless adults with psychiatric disorders
Hird R, Radhakrishnan R, Tsai J. A systematic review of approaches to improve medication adherence in homeless adults with psychiatric disorders. Frontiers In Psychiatry 2024, 14: 1339801. PMID: 38260790, PMCID: PMC10800888, DOI: 10.3389/fpsyt.2023.1339801.Peer-Reviewed Original ResearchMedication adherenceAssertive community treatmentLong-Acting Injectable MedicationsPsychiatric disordersInjectable medicationsAdherence enhancementCommunity treatmentHomeless adultsSystematic reviewPsychiatric medication adherenceSubstance use disordersFull-text reviewModified therapeutic communityPeer-reviewed journalsInpatient interventionLarge RCTsSelf-designed scaleHomeless individualsOutpatient interventionInpatient carePharmacy clinicObservational studyInclusion criteriaUse disordersPeer-reviewed studies
2023
PET Biomarkers in Psychiatry
Orhii P, Radhakrishnan R, Selvaraj S. PET Biomarkers in Psychiatry. 2023, 81-104. DOI: 10.1007/978-3-031-43356-6_6.Peer-Reviewed Original ResearchThe regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J
Toyonaga T, Khattar N, Wu Y, Lu Y, Naganawa M, Gallezot J, Matuskey D, Mecca A, Pittman B, Dias M, Nabulsi N, Finnema S, Chen M, Arnsten A, Radhakrishnan R, Skosnik P, D’Souza D, Esterlis I, Huang Y, van Dyck C, Carson R. The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [11C]UCB-J. European Journal Of Nuclear Medicine And Molecular Imaging 2023, 51: 1012-1022. PMID: 37955791, DOI: 10.1007/s00259-023-06487-8.Peer-Reviewed Original ResearchSynaptic densityAge-related decreaseMagnetic resonance imagingBlood flowAge-related synaptic lossGray matter volume lossSynaptic density lossPositron emission tomography (PET) ligandSynaptic vesicle glycoprotein 2AVivo PET measurementsMedial occipital cortexGray matter volumeAge-related neurodegenerationGray matter regionsCognitive normal subjectsAge-related changesSynaptic lossNerve terminalsWide age rangeOccipital cortexTomography ligandNormal subjectsGM volumeAge-related functional lossesMatter volume
Clinical Trials
Current Trials
M1 Schizophrenia PET Study
HIC ID2000031171RolePrincipal InvestigatorPrimary Completion Date04/30/2023Recruiting ParticipantsGenderBothAge18 years - 55 yearsImaging cortisol metabolism in liver, adipose tissue and brain with a novel PET radioligand
HIC ID2000029576RoleSub InvestigatorPrimary Completion Date06/30/2024Recruiting ParticipantsSchizophrenia Spectrum Biomarkers Consortium (SSBC)
HIC ID2000029485RoleSub InvestigatorPrimary Completion Date12/31/2030Recruiting ParticipantsTesting a Computationally-Informed, Personalized Intervention for Hallucinations
HIC ID2000024774RoleSub InvestigatorPrimary Completion Date03/31/2024Recruiting ParticipantsGenderBothAge18 years - 65 yearsA longitudinal study of the effects of cannabis exposure on neuro-development in adolescents and young adults
HIC ID2000024543RoleSub InvestigatorPrimary Completion Date01/31/2021Recruiting ParticipantsGenderBothAge13 years - 25 years
Academic Achievements & Community Involvement
Clinical Care
Overview
Rajiv Radhakrishnan, MD, is a psychiatrist who specializes in addiction medicine. He provides care for individuals with substance use disorders, offering strategies to manage cravings and withdrawal symptoms.
As an associate professor of psychiatry at Yale School of Medicine, Dr. Radhakrishnan investigates how certain substances can influence psychotic disorders like schizophrenia. He focuses on improving treatment approaches for people experiencing substance-induced psychosis.
Dr. Radhakrishnan completed his medical training at St. John’s Medical College and pursued further psychiatric training at Yale School of Medicine. He has been honored by the Society for Nuclear Medicine and Molecular Imaging, the American Society of Clinical Psychopharmacology, and the Society of Biological Psychiatry.
Clinical Specialties
Addiction Medicine; Psychiatry
Board Certifications
Addiction Medicine (Preventive Medicine)
- Certification Organization
- AB of Preventive Medicine
- Original Certification Date
- 2020
News
News
- December 13, 2024
Five Faculty Elected to Associate Membership of ACNP
- October 02, 2024
Bipolar Disorder Patients Respond to Ketamine, Esketamine Treatment
- April 02, 2024Source: Molecular Psychiatry
Substance Use and Spine Density: A Systematic Review and Meta-Analysis of Preclinical Studies
- December 18, 2022
Radhakrishnan Named Co-Medical Director of Yale PET Center