Electroconvulsive therapy (ECT) involves unilateral (sometimes bilateral) electrode placement over the nondominant hemisphere to induce tonic-clonic seizures under sedation. Although not fully understood, ECT likely causes anticonvulsant effects, brain remodeling, and improves brain perfusion. ECT is indicated for refractory cases, life-threatening symptoms (e.g., suicide risk), or special patient groups (e.g., pregnant patients) with certain mental disorders; including depression, schizoaffective disorder, and bipolar mood disorder. Complications include reversible memory loss, tension headaches, and transient muscle pain.
Usually indicated in the following conditions for refractory cases, cases in which a fast antidepressant effect is needed, when there are life-threatening symptoms; (e.g., severe suicidality, malnutrition due to food refusal, severe psychosis), or if medication is contraindicated (e.g., pregnancy): 
- Depression (most common)
- MDD with psychotic features
- Schizoaffective disorder
- Schizophrenia with catatonia
- Bipolar mood disorder (e.g., manic episodes)
- Highly suicidal or pregnant depressed patients (not usually first-line)
ECT is the most effective treatment for severe major depressive disorder.
- No absolute contraindications.
- Relative contraindications include:
Pregnancy and pacemakers are not a contraindication for ECT.
We list the most important contraindications. The selection is not exhaustive.
- General preparation and procedure 
- Unilateral electrode placement over the nondominant hemisphere
- EEG as well as constriction of the contralateral arm and ankle via blood pressure cuff for monitoring the seizure
- Administration of oxygen via face mask and preparation for emergency intubation if necessary
- ECG and pulse oximetry allow for monitoring further vital signs.
- Administration of premedications:
- Short-term general anesthesia, including a muscle relaxant (e.g., succinylcholine) to avoid risk of fractures
- An electric current is passed from one side of the cerebral cortex to the other.
- 6–12 sessions in total; consisting of generalized tonic-clonic convulsions that last 25–30 seconds, usually 2–3 times per week
- Treatment sessions can be discontinued once symptoms improve.
- Maintenance may be implemented once every 1–8 weeks.
- More common 
- Less common
- ECT itself is generally considered a safe procedure in all patients (including pregnant women and elderly individuals).
- The risk of mortality (due to cardiac or pulmonary compromise) is associated with anesthesia.
- If properly conducted, ECT is one of the safest procedures involving sedation.
- To date, no brain damage has been reported with the current method.