BACKGROUND: Treatment-resistant depression (TRD) is a growing clinical challenge. Electroconvulsive therapy (ECT) is an effective tool for TRD treatment. However, there remains a subset of patients who do not respond to this treatment with common anesthetic agent. Ketamine, a noteworthy anesthetic agent, has emerged as an augmentation to enhance the antidepressant efficacy of ECT. Trials of i.v. ketamine in TRD indicated dose-related mood enhancing efficacy. We aimed to explore anesthetic and subanesthetic concentrations of ketamine in ECT for TRD with respect to their impact on mood and neuropsychological effects.
METHODS: Ninety TRD patients (36 males, 54 females; average age, 30.6 years old) were randomly assigned to receive either ketamine (0.8mg/kg) (n=30), subanesthetic ketamine (0.5mg/kg) plus propofol (0.5mg/kg) (n=30) or propofol (0.8mg/kg) (n=30) as an anesthetic and underwent 8 ECT sessions. The primary outcome measures were the 17-item Hamilton Depression Rating Scale (HDRS-17), cognitive assessments and seizure parameters.
RESULTS: The ketamine group had an earlier improvement in HDRS-17, longer seizure duration, lower electric quantity, a higher remission rate, and a lower degree of executive cognitive impairment compared to the ketamine+propofol and propofol groups. The ketamine+propofol group showed earlier improvement in the HDRS-17, a longer seizure duration and a different seizure energy index when compared to the propofol group.
LIMITATIONS: The postoperative dissociative side effect was not assessed.
CONCLUSIONS: Both anesthetic and subanesthetic concentrations of ketamine have rapid mood enhancing actions in ECT for TRD, while anesthetic concentrations results in larger magnitudes of antidepression and cognitive protection. ECT with ketamine anesthesia might be an optimized therapy for patients with TRD.
