Key Facts

ECT remains one of the most effective treatments in psychiatry, particularly for severe and life-threatening depression. Despite public controversy, it is a safe, evidence-based treatment when used appropriately.

Epidemiology

Approximately 2,500-4,000 patients receive ECT annually in England. Use has declined over recent decades but remains an important treatment option for severe illness.

Aetiology

Mechanism of action (not fully understood):

• Generalised seizure activates multiple neurotransmitter systems simultaneously
• Anticonvulsant theory: Repeated seizures raise seizure threshold → normalises neural circuit hyperexcitability
• Neuroplasticity: Increases BDNF, promotes hippocampal neurogenesis
• Neuroendocrine: Normalises HPA axis dysregulation
• Neurotransmitter: Increases serotonin, noradrenaline, dopamine sensitivity; enhances GABAergic transmission

Pathophysiology

• Electrical stimulus (typically 0.5-1.0 seconds of brief-pulse current at 800mA) induces a generalised tonic-clonic seizure lasting 15-60 seconds
• Seizure must be adequate duration (≥15 seconds motor, ≥25 seconds EEG) for therapeutic effect
• The seizure, not the electrical current, produces the therapeutic effect

Indications (NICE TA59)

• Severe depressive illness — especially with psychotic features, suicidal ideation, refusal to eat/drink
• Catatonia — rapid, highly effective response
• Prolonged or severe mania — when other treatments have failed
• Treatment-resistant schizophrenia — augmentation of clozapine (limited evidence)
• Severe puerperal psychosis — particularly with catatonic features
• Life-threatening self-neglect — not eating or drinking due to depression/psychosis

Pre-ECT Assessment

• Full medical history and physical examination
• Anaesthetic assessment
• Baseline cognitive assessment (e.g., MoCA)
• Informed consent (or MHA provisions)
• Bloods: FBC, U&Es, ECG
• Consider CXR and CT head in older adults or if clinically indicated

Red Flags/Contraindications

• Absolute: Raised intracranial pressure, phaeochromocytoma
• Relative: Recent MI (<3 months), unstable angina, recent stroke, intracranial aneurysm, aortic/cerebral aneurysm, retinal detachment
• High-risk anaesthesia patients need careful assessment

Pre-ECT

• FBC, U&Es: Baseline bloods
• ECG: Cardiac assessment
• CXR: If clinically indicated
• Cognitive assessment: MoCA or MMSE — baseline for comparison
• Anaesthetic review: ASA grading

During Treatment

• EEG monitoring: Seizure duration and quality
• Motor seizure monitoring: Cuff technique (isolate limb from muscle relaxant to observe motor seizure)
• Vital signs: Continuous during and post-procedure

Post-Treatment

• Cognitive assessment: Repeat MoCA/MMSE at intervals
• Clinical rating scales: PHQ-9, HAM-D — monitor response

ECT Procedure

• General anaesthesia: Short-acting (propofol or thiopental)
• Muscle relaxant: Suxamethonium (to prevent injury from convulsion)
• Atropine/glycopyrrolate: May be used to reduce secretions and prevent bradycardia
• Electrode placement: Bilateral (more effective) or right unilateral (fewer cognitive effects)
• Stimulus: Brief-pulse (0.5-1.5ms) or ultra-brief pulse (0.3ms — less cognitive effects, may need higher charge)

Treatment Course

• Typically 6-12 sessions (twice weekly in UK)
• Assess response after each session and formally after 6 sessions
• Stop if no response after adequate trial
• Continuation/maintenance ECT: Consider for relapse prevention (weekly → fortnightly → monthly)

Post-ECT

• Continuation pharmacotherapy: Antidepressant (+ lithium augmentation) to prevent relapse
• Without maintenance treatment, relapse rate is ~50% within 6 months after ECT

Legal Framework

• Consent: Valid informed consent required
• MHA Section 58: If detained and lacks capacity or refuses — SOAD (Second Opinion Appointed Doctor) can authorise
• MHA Section 62: Emergency ECT without SOAD — life-threatening situations only
• MCA: If patient lacks capacity and is not detained, consider Court of Protection

Referral Criteria

• Specialist psychiatrist decision — discuss with patient and carers
• Anaesthetic assessment
• Consent/capacity assessment

• Response rates: 50-70% in treatment-resistant depression; higher (~80-90%) in severe depression with psychotic features
• Catatonia: >80% response rate — often dramatic improvement after first session
• Relapse: ~50% within 6 months without continuation treatment; continuation pharmacotherapy or maintenance ECT reduces this
• Cognitive effects: Short-term retrograde and anterograde amnesia is common; usually resolves within weeks to months; bilateral > unilateral; some patients report persistent memory difficulties
• Mortality: <1 in 50,000 treatments — similar to general anaesthesia risk for minor procedures

ECT Quick Reference