Table 2.

Key clinical evidence summary regarding ECT and psychiatric disorders.

Author *	Psychiatric Disorder	Methodology	Results
Diermen et al. [16]	Depression	Meta-analysis with 34 randomized controlled clinical trials evaluating the effects of ECT in patients with major depression.	The presence of psychotic features is a predictor of ECT remission (OR = 1.47, p = 0.001) and response (OR = 1.69, p < 0.001), as is older age (SMD = 0.26 for remission and 0.35 for response p < 0.001). The severity of depression predicts response (SMD = 0.19, p = 0.001) but not remission.
Elias et al. [135]	Depression	Meta-analysis with 5 randomized controlled clinical trials that assessed the efficacy of continuation ECT and maintenance ECT in preventing relapse and recurrence of depression.	Continuation ECT and maintenance ECT with pharmacotherapy were associated with significantly fewer relapses and recurrences than pharmacotherapy.
Ahmed et al. [19]	Schizophrenia	Meta-analysis with 9 randomized controlled clinical trials evaluating the effects of TEC in patients with resistant schizophrenia.	The ECT augmentation technique was found to be effective in the reduction of psychometric scale scores, and the resulting improvement was significant.
Bahji et al. [137]	Bipolar depression	Meta-analysis with 19 randomized controlled clinical trials evaluating the effects of TEC in patients with bipolar disorder in a resistant depressive episode.	The pooled response and remission rates with TEC in bipolar depression were 77.1% (n = 437/567) and 52.3% (n = 275/377), respectively. Response rates to TEC were statistically higher in bipolar depression than in unipolar depression (OR = 0.73, 95% CI: 0.56–0.95, p = 0.02).
Ueda et al. [9]	PDP	Retrospective study evaluating the influence of acute ECT on PDP.	The psychosis scores after ECT improved significantly compared with those before ECT.
Maletzky et al. [11]	OCD	Systematic review of 50 articles reporting the efficacy of the acute treatment of ECT for OCD.	A positive response was reported in 60.4% of the 265 cases that were studied.
Margoob et al. [12]	PTSD	An open, prospective study evaluating the influence of ECT in patients with severe, chronic, extensive antidepressant-refractory PTSD.	Scores evaluating PTSD significantly decreased by a mean of 34.4%.

* Search strategy: An exhaustive bibliographical search was performed using the terms “electroconvulsive therapy”, “neurobiological effects of electroconvulsive therapy”, “electroconvulsive therapy and immune system”, “electroconvulsive therapy and the endocrine system”, “molecular mechanisms in electroconvulsive therapy”, and “electroconvulsive therapy and psychiatric disorders”. The search was later filtered using the terms “humans” and “animals” as well as “clinical” and “preclinical”. For the selection of the studies, those that were published within the past 35 years were included. Abbreviations: ECT: electroconvulsive therapy; PDP: Parkinson’s disease psychosis; OCD: obsessive–compulsive disorder; PTSD: post-traumatic stress disorder.