Inflammation and Cognitive Functioning in Depressed Older Adults Treated With Electroconvulsive Therapy: A Prospective Cohort Study

ABSTRACT

Objective: Despite the effectiveness of electroconvulsive therapy (ECT), patients and practitioners are often reluctant to start it due to the risk of transient cognitive side effects, particularly in older patients. Inflammatory processes may be associated with the occurrence of these effects. This study assessed whether inflammatory markers prior to ECT are associated with cognitive functioning in depressed patients treated with ECT.

Methods: Between 2011 and 2013, 97 older patients (mean [SD] age = 73.1 [8.1] years) with severe unipolar depression (according to DSM-IV) referred for ECT were included. Mini-Mental State Examination (MMSE) scores were used to determine cognitive functioning prior to, weekly during, and in the first week after a course of ECT. Serum levels of C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) were assessed prior to ECT.

Results: In fully adjusted models, there was an association between TNF-α and cognitive functioning (β = −1.05; 95% CI, −2.04 to −0.06; f² = 0.06). An association was also found between baseline levels of IL-10 and TNF-α and lower MMSE scores during ECT (IL-10: β = −2.08; 95% CI, −3.22 to −0.95; TNF-α: β = −0.65; 95% CI, −1.07 to −0.22). In addition, an association was found between baseline CRP and lower MMSE scores directly after a course of ECT (β = −0.51; 95% CI, −0.93 to −0.09; f² = 0.10). Associations with IL-6 did not reach significance.

Conclusions: This study suggests that inflammatory processes are associated with lower cognitive functioning prior to ECT and predispose for further cognitive dysfunction during and after a course of ECT.

Trial registration: ClinicalTrials.gov identifier: NCT02667353