Inflammatory Biomarkers Have Little Clinical Utility in ECT for Depression

shock machine used in Electroconvulsive therapy
Close up of electro-shock machine used in Electroconvulsive therapy.
Investigators looked into whether there was any clinical relevance for inflammatory biomarkers in the setting of electroconvulsive therapy (ECT) for the treatment of depression.

A study published in Psychiatry Research failed to detect any clinical relevance for inflammatory biomarkers in the setting of electroconvulsive therapy (ECT) for the treatment of depression.

Patients (n=86) with depression were recruited for the Enhancing the Effectiveness of ECT in Severe Depression (EFFECT-Dep) trial in Ireland. Patients received 2 ECT sessions weekly while maintaining use of psychotropic medications. Fasting blood samples were obtained at baseline and after the last ECT session. Plasma concentrations of C reactive protein (CRP), interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α were compared with levels observed in controls (n=57) and were correlated with cognitive outcomes of ECT.

The patients and controls were aged mean 55.10 (SD, 14.65) and 50.96 (SD, 12.68) years, respectively, 61.63% and 33.33% were women, respectively, and baseline Hamilton depression rating scale (HAM-D) was 31.14 (SD, 6.54) and 2.70 (SD, 1.99) points (P <.001), respectively.

The patients received an average of 8.03 (SD, 2.51) ECT sessions, 52.33% received bitemporal stimulation, the ECT stimulus charge was 459.31 (SD, 234.04) mC, and 62.79% responded to treatment.

Compared with the controls, CRP, IL-6, IL-10, and TNF-α concentrations were significantly higher (all P ≤.006) but only IL-6 (F[1,112], 7.94; P =.006) and TNF-α (F[1,115], 6.53; P =.01) remained significant after adjusting for covariates.

Stratified by depression symptomology, significant differences were observed among patients with unipolar or bipolar depression groups and psychotic and nonpsychotic depression groups compared with controls, but there were no between-group patient differences observed.

Among the patients, the pre- and post-ECT circulating levels of CRP, IL-6, IL-10, and TNF-α did not differ significantly. After removing patients who were taking nonsteroidal anti-inflammatory drugs, TNF-α levels were significantly increased post-ECT, however, given the small effect size (d, 0.09) the difference was not likely to be clinically meaningful. Stratifying by depression symptomology did not reveal any significant trends.

No associations between HAM-D or cognition scores and inflammatory markers were observed.

A potential limitation of this study was the continued use of pharmacotherapy during the study.

The study authors concluded, “Overall, our results replicate previous findings of significantly raised IL-6 and TNF-α concentrations in depressed patients. […] While further studies are required to fully assess the relationship between ECT and the immune-inflammatory response, it seems unlikely that these inflammatory mediators will be useful as clinical biomarkers in ECT practice.”

Disclosure: An author declared affiliations with industry. Please refer to the original article for a full list of disclosures.


Ryan KM, McLoughlin DM. Peripheral blood inflammatory markers in depression: response to electroconvulsive therapy and relationship with cognitive performance. Psychiatry Res. 2022;315:114725. doi:10.1016/j.psychres.2022.114725