A Phase 4 interventional study of Clonidine and Placebo in Major Depressive Disorder, Catatonia and Bipolar Disorder, sponsored by Insel Gruppe AG, University Hospital Bern. Completed at 1 site in Switzerland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-19.
Sponsored by Insel Gruppe AG, University Hospital Bern · Phase 4, Interventional, and Prevention
Electroconvulsive therapy (ECT) is a highly effective treatment for some psychiatric disorders like major depressive or bipolar disorder, but may lead to agitation and delirium after the procedure in up to 65% of patients. This can have negative side effects and be dangerous for patient and attending staff. Clonidine, a central-acting alpha2-receptor agonist, is an approved antihypertensive medication with known sedative side effects. Clonidine's newer but more expensive successor, dexmedetomidine, has recently shown its potential to reduce this kind of delirium. The investigators therefore hypothesise that pre-treatment with 2 mcg/kg clonidine prior to electroconvulsive therapy will significantly reduce the incidence of postictal delirium. This potentially makes a highly efficient treatment for patients with otherwise refractory psychiatric illness safer and more accessible.
Electroconvulsive therapy (ECT) is a highly efficacious therapy for psychiatric disorders, especially major depressive disorder, bipolar disorder and catatonia resistant to psychopharmacology or drug-psychotherapy combination therapy. At therapy induction, usually a series of 10-12 ECT sessions is planned with two to three days in between sessions. Thereafter, maintenance therapy can be continued with longer session intervals thereafter to avoid relapses and to support further drug and psychotherapy treatment. Without maintenance therapy, relapses can happen in up to 80% of all patients within one year.
Nowadays conducted under general anaesthesia (etomidate in the investigator's centre) and muscle relaxation (suxamethonium) to prevent adverse events, ECT can be challenging for the anaesthesiologist, as it usually leads to rapid cardiovascular changes such as sudden bradycardia due to vagal discharge, followed by sympathetic counter regulation associated with tachycardia and hypertension. For the patient, known immediate side effects are headache in about 30% and postictal confusion and delirium in up to 65%. This confusional state can lead to involuntary movements and agitation and therefore be harmful for patients and attending staff. It usually resolves within 45 minutes but nevertheless seems to be linked with adverse side effects like persistent retrograde amnesia. Identified risk factors are long seizure time and pre-existing catatonic features. Postictal delirium has been classified by Kikuchi et. al. into four categories from no delirium, mild, moderate or severe delirium. Moderate to severe delirium needing restraints or sedative medication like benzodiazepines or Propofol was present 36% of patients, which is in line with older data. The more severe forms of delirium are easily recognised in clinical practice because of the need for intervention. When including mild forms, delirium was present in 52% of all patients in the study of Kikuchi et al. In newer studies using a more sensitive tool (CAM-ICU, Confusion Assessment Method - Intensive Care Unit) to assess the presence of delirium, the rates are up to 65% at 10 minutes after ECT stimulation respectively 10 minutes after arrival in the post-anaesthesia care unit. CAM-ICU is a brief but sensitive test, which has been extensively validated in the intensive care setting. Therefore, it seems that postictal delirium is frequently underdiagnosed in clinical practice. As we know from the intensive care literature, even hypoactive forms of delirium are associated with higher complication rates and higher mortality and therefore cannot be neglected.
In previous small studies, premedication with promethazine, midazolam and dexmedetomidine successfully reduced incidence of postictal delirium. Dexmedetomidine, a highly selective, relatively short acting alpha2-agonist, has been more extensively studied in the setting of ECT and has recently been able to show his potency to reduce postictal delirium by a third when given as a bolus pre-induction in a randomised controlled trial.
In this prospective, randomised, placebo-controlled, triple-blind, single-centre, two-arm parallel groups superiority trial, the investigators aim to lower incidence and severity of postictal delirium and agitation using a pre-induction dose of 2 mcg/kg clonidine intravenously compared to placebo (sodium chloride). The investigators also hypothesise, that a pre-induction dose of clonidine will reduce incidence of postictal agitation, the need for sedative rescue medication and the need for short-acting antihypertensive medication. It therefore might increase patient safety and cost effectiveness without prolonging post-anaesthesia care unit stay or negatively affecting treatment efficacy.
3,041 studies on the registry are indexed under Depressive Disorder, Major; 588 are open to participants now.
This study's enrollment of 130 is above the median of 79 across 2,530 interventional studies indexed under Depressive Disorder, Major.
Browse Depressive Disorder, Major studies →Insel Gruppe AG, University Hospital Bern is the lead sponsor of 741 studies on the registry; 180 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study drug (clonidine 2 mcg/kg) is diluted in 100 ml sodium chloride 0.9 % by trained post-anaesthesia care staff not involved in the study. At admission, electrocardiogram, non-invasive blood pressure and pulse oximetry is installed, a peripheral venous line established and supplemental oxygen applied. The study drug will be given intravenously over 10 minutes at least 10 minutes before induction of anaesthesia. Electroconvulsive therapy will be conducted according to hospital standard (Etomidate 0.2 mg/kg, Suxamethonium 1.0 mg/kg, isolated limb technique, THYMATRON® SYSTEM IV, Somatics Inc., Lake Bluf, Illinois, USA) adjusted to the patient's condition. Seizure quality will be assessed, prolonged seizure activity terminated with propofol 0.2 - 0.3 mg/kg. Severe agitation (Richmond Agitation and Sedation Score (RASS) \> 1) needing intervention will be treated with propofol or lorazepam. Patients will be assessed for delirium using CAM-ICU at 20 minutes after induction.
Drug: Clonidine
The placebo will be created by diluting 1ml of sodium chloride 0.9% in 100ml of sodium chloride in a sterile manner prior to application. The container will be identically labelled as the verum. The placebo will be applied by the same team members named above via the same route (intravenously), with the same speed and the same timing. All other parts of the procedure are identical as to the procedure described above.
Drug: Placebo
Clonidine 2mcg/kg Body Weight diluted in 100ml sodium chloride 0.9% compared to placebo (sodium chloride 0.9% alone) given over 10 minutes, 10 minutes prior to electroconvulsive therapy.
Also known as: Verum
Sodium chloride 0.9% 100ml given over 10minutes, 10 minutes prior to electroconvulsive therapy.
Incidence of delirium after electroconvulsive therapy over all (twelve) ECT sessions
The primary outcome is delirium after electroconvulsive therapy over all (twelve) ECT sessions. The presence of delirium will be assessed using Confusion Assessment Method - Intensive Care Unit (CAM-ICU). To be able to perform the test correctly, the patient must be awake enough. This will be assessed using the Richmond-Agitation-Sedation-Scale (RASS) first ranging from -5 (unarousable) to +4 (combative)
Time frame: 20 minutes after muscle relaxation
Incidence of mild agitation
RASS +1, needing verbal command or short restraint \< 1 minute
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Incidence of severe agitation
RASS \> 1, needing restraint \> 1 minute or rescue medication)
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Use of rescue medication
medication, dose, route
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Duration of seizure activity
seconds
Time frame: during procedure (estimated to be on average 10-15 minutes)
Quality of seizure activity
ideal, sufficient, insufficient
Time frame: during procedure (estimated to be on average 10-15 minutes)
Seizure Quality Index
Seizure Quality Index (Kranaster et al., Eur Arch Psychiatry Clin Neurosci 2018) ranging from 0 to 5. Higher index indicates better response to treatment.
Time frame: during procedure (estimated to be on average 10-15 minutes)
Need for seizure terminating medication
medication, dose, route
Time frame: during procedure (estimated to be on average 10-15 minutes)
Total number of electroconvulsive therapy sessions
number
Time frame: whole treatment course (12 ECT sessions, about 4 weeks)
Reason for terminating or continuing the electroconvulsive series
failure, response, remission, other reason
Time frame: whole treatment course (12 ECT sessions, about 4 weeks)
Length of post-anaesthesia care unit stay
minutes
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Incidence of desaturation
Oxygen saturation by pulse oximetry \< 75%, irrespective of duration
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Incidence of hypotension
any measurement with mean arterial pressure \< 55 mmHg
Time frame: during procedure (estimated to be on average 10-15 minutes)
Incidence of bradycardia
heart rate \< 50 bpm for more than 1 minute
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Cardiovascular changes needing intervention
number and type
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Use of cardiovascular medication
medication, dose, route
Time frame: post-anaesthesia care unit stay (up to 2 hours)
Adverse events potentially attributable to ECT
diagnosis
Time frame: whole treatment course (12 ECT sessions, about 4 weeks)
Adverse events potentially attributable to Study Drug
diagnosis
Time frame: whole treatment course (12 ECT sessions, about 4 weeks)
Plan to share: No
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Ran from Apr 2021 to primary completion in May 2026, 60 months.
Of 79 non-industry phase 4 interventional studies under Depressive Disorder, Major, half reached primary completion within 45 months of starting (the median), counting those still running; a quarter within 25 and three quarters within 60. This study's 60 months is above that.
Counting every sponsor, half of 98 studies reached it within 35 months; a quarter within 20 and three quarters within 58.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Clonidine
Insel Gruppe AG, University Hospital Bern →