• bipolar disorder
• late-onset bipolar disorder
• mixed state
• electroconvulsive therapy
• depression
• bipolar elderly patients
• cerebral small vessel disease
• catatonia

Background: Over 25% of all bipolar disorder (BD) patients are elderly, with late-onset bipolar disorder (LOBD) often linked to neuroprogression and neurodegeneration. Cerebral small vessel disease (CSVD), a common and progressive vascular disorder in the elderly, contributes significantly to various neurological and psychiatric conditions. Major affective episodes in this demographic are associated with high morbidity and mortality, necessitating urgent interventions. Electroconvulsive therapy (ECT) is a highly effective first-line treatment for severe clinical conditions, such as treatment-resistant depression, mixed states, and mania, with response rates between 70% and over 90%.
Aim of the study: The effectiveness of ECT was evaluated in non-demented elderly patients (≥ 60 years) with LOBD and treatment-resistant major depression, mixed state, or catatonia. Specifically, the response rates and symptoms improvement after ECT were assessed to determine whether CSVD might influence ECT outcomes.
Materials and Methods: This naturalistic and observational study was conducted in a cohort of 54 treatment-resistant patients who underwent bilateral ECT between January 2006 and August 2023. All patients were evaluated prior to and after the ECT course using the Brief Psychiatric Rating Scale (BPRS), the Young Mania Rating Scale (YMRS), the Hamilton Rating Scale for Depression (HAM-D), and the Clinical Global Impression scale (CGI). A diagnosis of CSVD was established based on brain neuroimaging performed before ECT.
Results: No significant differences were observed between patients with and without CSVD at baseline. 37 patients (68.6%) responded to ECT according to CGI-I, with similar response rates in patients without (n = 25, 71,7%) and with CSVD (n = 12, 63,2%). No significant differences in ECT outcomes nor in longitudinal changes of rating scale scores were found between groups.
Conclusion: To the best of our knowledge, our study is the first to investigate the impact of CSVD, as identified through CT or MRI brain scans, on a cohort of non-demented, treatment-resistant elderly patients with LOBD. Response to ECT in bipolar depression, mixed states, and catatonia was not influenced by the presence of CSVD. This finding aligns with previous research on unipolar elderly depressed patients. ECT should be considered for elderly patients with BD, regardless of the presence of CSVD.