Gregory M. Nikogosyan, DO, MBA

All Publications

• Equivalent efficacy of left versus right hemisphere accelerated intermittent theta burst stimulation for major depressive disorder. Frontiers in psychiatry Quinn, D. K., Upston, J., Jones, T. R., Olmstead, T. A., Yang, J., Reyes, S., MacDonald, S., Littleton, A., Win, A., Bowers-Wu, D. H., Lee, J. G., Huynh, P., DeBurlo, R. T., Velasco, A., Nakip, A., Richardson, E. R., Davis, J. R., Hazlewood, S., Garcia, C. A., Ojeda, C. J., Luo, K., David, J., Gibson, B. C., Nikogosyan, G. M., Hager, B. W., Farrar, D., Myers, O., Vakhtin, A. A., Abbott, C. C. 2026; 17: 1745388

  Abstract

  Intermittent theta burst stimulation (iTBS) to the dorsolateral prefrontal cortex (DLPFC) for major depression has been FDA-approved in the United States since 2018. Accelerated iTBS (aiTBS) protocols of multiple treatments per day have shown promising response and remission rates for major depression, especially when combined with connectivity-guided targeting. Brain networks associated with emotion regulation demonstrate significant changes in connectivity after effective iTBS. However, these findings have been confined to treatment of the left DLPFC, despite literature suggesting equivalent outcomes with right side stimulation. To date there has not been a direct comparison of clinical outcomes and connectivity changes between left and right DLPFC aiTBS for depression.Forty-four patients aged 50-79 with chronic major depressive disorder underwent open-label accelerated fMRI-guided aiTBS (45 sessions, 9 days) to the DLPFC (18 left, 26 right). Depression, anxiety, and anhedonia symptoms were assessed, and resting-state fMRI was obtained at baseline (Visit 1), after 15 sessions (Visit 2), and end of treatment (Visit 3). Patients who were not demonstrating at least 10% improvement in depression at Visit 2 were switched to contralateral stimulation for the remaining 30 sessions.For the entire cohort (N = 44), mean depression (IDS-C30) scores decreased significantly over the course of treatment. Mean change in IDS-C30, GAD-7, TEPS, SHAPS, and BISBAS between participants with right-sided stimulation (N = 26) and those with left-sided stimulation (N = 18) were not statistically different. Functional connectivity analysis demonstrated significant decreases in connectivity from Visit 1 to Visit 3 between default mode network and limbic networks in patients receiving right DLPFC iTBS, whereas patients receiving left DLPFC iTBS demonstrated limited changes in connectivity.Accelerated iTBS to the right DLPFC appears to have equivalent efficacy as aiTBS to the left DLPFC in terms of magnitude of reduction of depressive, anxious, and anhedonic symptoms in a late-life population. However, connectivity changes associated with treatment were asymmetric, and may reflect hemispheric lateralization of functional network responses to iTBS. Further work is needed to confirm the comparative efficacy and network dynamics of left versus right hemisphere aiTBS for depression.

  View details for DOI 10.3389/fpsyt.2026.1745388

  View details for PubMedID 41890433

  View details for PubMedCentralID PMC13014255

• Tardive Dystonia and Electroconvulsive Therapy: A Case Presentation and Scoping Review MacDonald, S., Yang, J., Torncello, E., Kloster, W., Nikogosyan, G. ELSEVIER SCIENCE INC. 2025

  View details for DOI 10.1016/j.jaclp.2025.10.278

  View details for Web of Science ID 001632287200030

• A Case of Prosopometamorphopsia and Motor Disturbances After Recovery From Methamphetamine Overdose Torncello, E., Khan, F., MacDonald, S., Nikogosyan, G. ELSEVIER SCIENCE INC. 2025

  View details for DOI 10.1016/j.jaclp.2025.10.038

  View details for Web of Science ID 001632245200009

• Secondary Mania of Medical and Neurological Disorders Mania and Hypomania – Symptoms, Causes, and Treatment Nikogosyan, G. M., Torncello, E. R., MacDonald, S. I. IntechOpen. 2024

  View details for DOI 10.5772/intechopen.1007693

• Atypical NMS and Third Generation Antipsychotic Medications: A Systematic Literature Review and Comparison with International Expert Consensus NMS Diagnostic Criteria Nikogosyan, G., Nunes, J., Caro, M. ELSEVIER SCIENCE INC. 2023: S130

  View details for DOI 10.1016/j.jaclp.2023.11.262

  View details for Web of Science ID 001161339100246

• Implications for a System of Care in Hawai'i for Criminal Justice and Substance Use. Hawai'i journal of health & social welfare Redulla, J. K., Nikogosyan, G. 2022; 81 (12 Suppl 3): 12-18

  Abstract

  Significant opportunities to improve treatment for substance use disorders can occur within the criminal justice system. This article will review the current system of care, understand current interventions available, and explore recommendations to better address community needs. With rising numbers of substance use and substance related deaths, this threat to the community is predicted to only worsen without intervention. There are multiple points in the justice system throughout the pretrial, court, and sentencing periods where the opportunity to help people with substance use disorder may occur. These points of diversion can focus on a more rehabilitative approach to crimes in the context of substance use disorder rather than punitive incarceration without adequate treatment. Police diversion can be increased and new police metrics incentivizing such efforts can be implemented in place of informal disposition by officers. Further training of law enforcement officers and continued development of support staff will help change practice allowing those with substance use disorders in the criminal justice system to connect to appropriate services. Data collection for research and analysis of recidivism among those engaged with diversion services compared to those who have not will help further guide future policy and resources for such programs.

  View details for DOI 10.1002/bsl.738

  View details for PubMedID 36660276

  View details for PubMedCentralID PMC9783817

• A Survey of Geriatric Psychiatry Fellows and Program Directors: Specialty Choice, Program Choice, and Program Quality. Academic psychiatry : the journal of the American Association of Directors of Psychiatric Residency Training and the Association for Academic Psychiatry Agapoff, J. R., Maixner, S., Takeshita, J., Nikogosyan, G., Kirwin, P. 2022; 46 (4): 455-459

  Abstract

  This study explored factors influencing a physician's choice to pursue geriatric psychiatry fellowship training from fellow and program director perspectives to improve recruitment into this critical need specialty.Questionnaires were sent to the 54 fellows and 79 fellowship program directors of programs accredited by the Accreditation Council for Graduate Medical Education (ACGME) available through the American Association for Geriatric Psychiatry (AAGP) listserv. A 5-point Likert scale (strongly disagree, disagree, neutral-undecided, somewhat agree, strongly agree) was used to score and rank these questionnaires.Thirty-three program directors (42%) on the AAGP listserv and 24 (44%) of all ACGME accredited fellows responded. The clinical quality of the faculty (Fellows 92%, Program Directors 92%) and the fellowship's national reputation (Fellows 75%, Program Directors 88%) were most highly ranked by both. Fellows ranked proximity to family (79%) high (2nd) in their program choice, while ranking workload, salary, and visa issues as low.This study emphasizes that family and cultural/ethnographic considerations, along with the core values of a training program, remain highly valued by trainees, and should inform structural changes to incentivize training, and enhance the inherent quality of fellowship programs.

  View details for DOI 10.1007/s40596-022-01611-6

  View details for PubMedID 35257318

  View details for PubMedCentralID 7957467

• Acute Aripiprazole-Associated Liver Injury. Journal of clinical psychopharmacology Nikogosyan, G., Orias, D., Goebert, D., Takeshita, J., Wang, M. 2021; 41 (3): 344-346

  View details for DOI 10.1097/JCP.0000000000001372

  View details for PubMedID 33734168

• Novel synthesis of physovenine and physostigmine analogs TETRAHEDRON LETTERS Wang, C. H., Alluri, S., Nikogosyan, G., DeCarlo, C., Monteiro, C., Mabagos, G., Feng, H. H., White, A. R., Bartolini, M., Andrisano, V., Zhang, L. K., Ganguly, A. K. 2016; 57 (27-28): 3046-3049

  View details for DOI 10.1016/j.tetlet.2016.06.005

  View details for Web of Science ID 000378667600025