Cognitive Profiles in Treatment-Resistant Late-Life Depression and the Impact on rTMS Treatment Outcomes

Poster Session C - Sunday, April 14, 2024, 5:00 – 7:00 pm EDT, Sheraton Hall ABC

Katharina Göke¹, Shawn M. McClintock², Alisson P. Trevizol^1,3, Linda Mah^3,4,5, Tarek K. Rajji^1,3,5, Sean M. Nestor⁶, Jonathan Downar⁴, Yoshihiro Noda⁷, Zafiris J. Daskalakis⁸, Benoit H. Mulsant^1,3, Daniel M. Blumberger^1,3; ¹Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ²Division of Psychology, Department of Psychiatry, University of Texas Southwestern Medical Center, ³Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, ⁴Rotman Research Institute, Baycrest Health Sciences, Toronto, ⁵Toronto Dementia Research Alliance, University of Toronto, ⁶Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Toronto, ⁷Department of Neuropsychiatry, Faculty of Medicine, Keio University School of Medicine, ⁸Department of Psychiatry, University of California

Late-life depression (LLD) is frequently linked to cognitive impairment, yet substantial heterogeneity exists among individuals. Data on the extent and frequency of cognitive impairments are inconclusive, particularly in treatment-resistant depression (TRD). This study aimed to investigate cognitive profiles of older adults with TRD vs. non-TRD and identify distinct cognitive subgroups among individuals with LLD. Additionally, we examined whether cognitive subgroups differentially responded to treatment with bilateral repetitive transcranial magnetic stimulation (rTMS). A total of 165 patients with LLD were subdivided into treatment-resistant and nonresistant groups and compared to healthy controls (HC) on measures of executive function, information processing speed, verbal learning, and memory. Cluster analysis was conducted to identify subgroups within the LLD group based on cognitive scores. Demographic and clinical variables, as well as outcomes with bilateral rTMS were compared between the cognitive subgroups. We found that patients with LLD exhibited significantly worse performance across most cognitive measures compared to HC, and these impairments were more pronounced in TRD. A three-cluster solution emerged, including “Cognitively Intact” (n = 89), “Cognitively Diminished” (n = 29), and “Impaired Memory” (n = 47) groups. Both the “Cognitively Diminished” and “Impaired Memory” groups had more anxiety symptoms than the “Cognitively Intact” group. No significant differences were observed in other variables, nor in the response to rTMS treatment. Future research is needed to determine the relationship of cognitive subgroups with risk for further cognitive worsening and neurodegeneration.

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