## Mechanism of ECT **Key Point:** ECT works by inducing a controlled generalized seizure under anesthesia, which triggers neurobiological changes that alleviate severe psychiatric symptoms. ### Primary Mechanism The therapeutic benefit of ECT arises from: 1. **Seizure induction** — electrical stimulus triggers a generalized tonic-clonic seizure lasting 20–60 seconds 2. **Neurochemical changes** — acute seizure activity increases: - Monoamine neurotransmitter release (serotonin, norepinephrine, dopamine) - GABA and other inhibitory neurotransmitter activity - Endogenous opioid peptides 3. **Synaptic plasticity** — repeated ECT sessions enhance long-term potentiation and neurogenesis in the hippocampus 4. **Neuroendocrine effects** — altered HPA axis function and prolactin release **High-Yield:** The seizure itself is essential; ECT without seizure induction ("sham ECT") is ineffective. The duration and quality of the seizure correlate with clinical response. **Clinical Pearl:** ECT is NOT a destructive procedure — it is reversible and does not cause permanent brain damage. Modern anesthesia and muscle relaxants make it safe and well-tolerated. ### Why Other Options Are Wrong - Direct neural destruction would cause permanent deficits and is not the mechanism - Seizure threshold elevation is a side effect, not the therapeutic mechanism - Ablation is irreversible and not how ECT works [cite:Kaplan & Sadock's Comprehensive Textbook of Psychiatry 11e Ch 35]
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