A systematic review of 42 studies examined predictors of response to electroconvulsive therapy, repetitive transcranial magnetic stimulation, and ketamine-based treatments in adults with treatment-resistant depression. Predictive factors were grouped into clinical (symptom profile, illness duration), biological (IL-6, CRP, BDNF), and imaging (cingulate cortex activity, connectivity) categories. Inflammation markers and fronto-limbic network findings appeared across treatments but were inconsistent. Some predictors show promise, but clinical use remains limited by methodological differences and small sample sizes. Larger and comparative studies are needed to identify clinically useful predictors for treatment decision-making.
A systematic review of 42 studies examined factors that might predict which adults with treatment-resistant depression respond to electroconvulsive therapy, repetitive transcranial magnetic stimulation, or ketamine-based treatments. Predictive factors were grouped into clinical (symptom profile, illness duration), biological (inflammatory markers such as IL-6 and CRP, and BDNF), and imaging (cingulate cortex activity and connectivity). Some inflammation markers and fronto-limbic network findings appeared across treatments, but results were inconsistent. The review found weak evidence for a few predictors, but no consistent or clinically useful factors emerged for any modality or for comparing effectiveness between treatments. Larger, comparative studies are needed.