Electroconvulsive Therapy

Electroconvulsive therapy (ECT) has been around since the 1930s. It was originally tried in schizophrenia but it was soon shown to benefit patients with mood disorders. It was originally used without either anaesthesia or muscle relaxants and patients suffered significant injury.

ECT has stimulated mixed opinions both amongst the lay population and the medical profession. Some groups think it is harmful and invades patient autonomy and others feel that it is useful when performed under appropriate circumstances and if the risks and benefits are weighed.

• Electrodes are placed on the skull. They can be placed on one side (unilateral ECT - usually on the non-dominant hemisphere) or both sides (bilateral ECT).
• Patients are given a general anaesthetic and a muscle relaxant.
• Subsequently an electrical current is delivered to induce a generalised seizure.
• The patient has about 6 - 12 sessions, approximately twice a week. If the patient responds then sessions are stopped. Rarely, ECT is used in maintenance therapy, about once a month.

It is unclear how ECT works. However, it is hypothesised that it leads to increased release of neurotransmitters or enhances the response of postsynaptic receptors to brain chemicals.

NICE recommend ECT for rapid improvement in the short-term of symptoms in the following:¹

• Severe depressive illness or refractory depression.
• Catatonia
• Prolonged or severe episode of mania

It should only be used if other treatment options have failed or the condition is potentially life-threatening (e.g. personal suffering, social impairment or high suicide risk).

• ECT is usually only used in the short-term and long-term benefits have not been documented. ECT should stop once a response is achieved or if the patient develops side effects. Also if the patient refuses further treatments then ECT should stop.¹
• Note that ECT is not useful in schizophrenia as the evidence is conflicting.²
• Furthermore, the cost effectiveness of ECT has not been decided.³

• Decisions to use ECT should only be made by mental health specialists.
• Decisions are based on weighing the risks and benefits to the patient.
• Risk analysis includes the risk of the anaesthetic, risk of having no treatment and side-effects.
• Elderly patients and children are at increased risk.
• Pregnant women are at an increased risk.
• Decisions should be made in partnership with the patient if possible. The patient must give their consent if they have the capacity to do so.¹
• If patients are unable to consent then the decision will need to be made in the patients best interests - it may be helpful to involve family and carers for advice.⁴

• ECT in Catatonia:
  • Catatonia is associated with an alteration in muscle tone which can lead to the absence of movement or excessive movement.
  • It is seen in schizophrenia and mood disorders.
  • It is usually treated with benzodiazepines but occasionally patients require ECT. However, the benefit with ECT in catatonia has not been clearly evaluated and most evidence is based on case reports.
• ECT in Mania:
  • During a manic episode patients have an elevated mood and increased energy. During a severe episode patients are potentially dangerous to themselves and possibly others.
  • ECT is occasionally used, although antipsychotics are the mainstay of treatment. The evidence for the effectiveness of ECT is unclear.⁵
• ECT in Depression:
  • ECT is used in severe depressive episodes e.g. depression with delusions and hallucinations. It may also need to be considered if patients become suicidal or homicidal.⁶
  • A systematic review and meta-analysis confirmed that ECT is effective in depression in the short-term. Furthermore, ECT may be more effective than drug therapy in depression.^7,8

Real ECT has been compared with sham ECT. These trials have shown that ECT is more effective in the short-term. Also, bilateral treatments are more effective than unilateral. These results have been seen in conditions such as depressive illness and mania.^1,9

On the other hand, a review of trials of schizophrenia and ECT have revealed that there is no clear benefit. Also there have not been any comparisons between ECT and established antipsychotics e.g. clozapine.²
Further research is required and needs to include long-term effects and safety and role in certain groups e.g. elderly patients.¹⁰

Immediate

• Cardiovascular instability e.g. arrhythmias and hypotension
• Status epilepticus
• Related to the general anaesthetic
• Laryngospasm
• Peripheral nerve palsies
• Headache
• Nausea

Long-term

• ECT is associated with long-term and short-term memory deficits.
  • This can affect anterograde and retrograde memory.¹¹
  • The deficit is greater if the patient receives bilateral rather than unilateral ECT. It is also more apparent with unilateral ECT when electrodes are placed on the dominant side of the brain.
  • Memory changes are more marked with increasing number of treatments and the type of stimulus delivered.
  • Changes in memory from ECT can be severe and very distressing for the patient. This can counteract any intended benefits.
  • The cause of memory deficit is not known and brain imaging is normal. Some argue that the memory impairment is due to the underlying psychiatric condition rather than the ECT.

Mortality from ECT is not more than mortality from a general anaesthetic when undergoing minor surgery.