The underlying diagnoses in catatonic patients can be affective disorder, schizophrenia, schizoaffective disorder and a range of medical/neurological illnesses. Benzodiazepine and 6 to 12 sessions of electroconvulsive therapy (ECT) have been considered the first-line treatments for almost all types of catatonia.

To discuss when ECT should be started, its risks and lateral effects, pointing the maximum number of sessions and if there are patients that need a higher number of ECT than what is referred in literature.

A revision about catatonia etiology, diagnosis and treatment was done, based on two clinical cases.

The number of ECTs recommend in literature is 6 to 12, and although there isn’t a maximum number defined, the treatment should be reconsidered if there isn’t response after 6 sessions. The lateral effects of higher ECT number are not known to differ with ECT number. We present a case of a 63 years old woman with major depressive and catatonia whose symptoms only resolved after the 21 ECT, with a previous psychotic depression treated with 17 ECT. The second case is a 60 years old woman with the diagnosis of paranoid schizophrenia with catatonic symptoms that only recovered after 17 ECT. In both patients, the clinical improvements where noticed only after a higher number of sessions.

The maximum ECT number should be adapted to each patient and the clinical response obtained, always considering the possibility of exceeding the numbers recommended in literature.