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Dr Michael Hunter
+44 (0)114 2716231
m.d.hunter@shef.ac.uk


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Be Part of Research - Trial Details - A double-blind randomised controlled trial of repetitive Transcranial Magnetic Stimulation (rTMS) in the treatment of persistent auditory hallucinations in schizophrenia
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A double-blind randomised controlled trial of repetitive Transcranial Magnetic Stimulation (rTMS) in the treatment of persistent auditory hallucinations in schizophrenia

Not Recruiting

Open to: All Genders

Age: Adult

Sheffield

Medical Conditions

Mental and Behavioural Disorders: Schizophrenia

This information is provided directly by researchers and we recognise that it isn't always easy to understand. We are working with researchers to improve the accessibility of this information.


Not provided at time of registration

Start dates may differ between countries and research sites. The research team are responsible for keeping the information up-to-date.  

The recruitment start and end dates are as follows:

01 Dec 2001 30 Nov 2004

Interventional

Intervention Type : Other
Intervention Description : Participants:Hoffman et al (2000) found a change of four from baseline in the hallucination score with standard deviation six, comparing sham and active treatments. To detect this will require about 26 patients in each cell for 90% power and 5% significance. To compare left rTMS against control, assuming that right rTMS is ineffective will then yield 52 patients per arm. To compare any active treatment with sham will yield 78 patients in the active arm and 26 in the control. This 3:1 ratio will reduce the power slightly to give 80% confidence in detecting a change of 4.5 units of hallucination score.

The statistical power calculation requires a total of 104 subjects to enable the study to detect the predicted outcomes. All Sheffield general psychiatry consultant teams will be contacted and invited to refer from their in-patient and out-patient caseload.

A drop-out rate of 10% is predicted. We will, therefore, recruit 20% more subjects than is required by the power calculation (126 in total) in order to take account of this and any compliance problems. We aim to recruit patients at a rate of seven per month, which will give a total of 126 patients over 18 months. In Sheffield, between April 1999-April 2000, there were 475 patients with schizophrenia aged more than 18 years who had recorded clinical contact with mental health services. The planned recruitment is compatible with this number of potential subjects, and is particularly facilitated by the closeness of contact between such patients and mental health services. Divergence from target rates by month 12 will prompt possible extension of trial to other local Trusts, e.g. Rotherham and Doncaster, which will expand the total population to in excess of 1.1 million and give an estimated total of 950 potential subjects.

Interventions:The study will be a factorial, double-blind, randomised controlled trial. Throughout the trial, all subjects will continue to receive standard care from their responsible consultant psychiatrist. No restrictions will apply to the changes that may be made to standard care during the study.

Subjects will be randomised into one of the four arms of the factorial design. Randomisation will proceed in a stratified manner, matching the groups for age, sex, handedness and severity of auditory hallucinations. Subjects will be blind to their experimental allocation.

The procedure in each of the four arms will be administered to the subjects once daily for ten consecutive working days. Prior to commencing treatment each subject in an active rTMS arm will have their Motor Threshold (MT) determined by the application of single pulses of TMS over the motor cortex. All rTMS will be administered by a doctor in the ECT suite or comparable environment.

The four arms of the trial and the associated interventions are:A. Left only: rTMS at a frequency of 1 Hz and amplitude 100% MT applied to left temporal cortex for 20 minutes.B. Right only: rTMS at a frequency of 1 Hz and amplitude 100% MT applied to right temporal cortex for 20 minutes.C. Left and right: rTMS at a frequency of 1 Hz and amplitude 100% MT applied to left temporal cortex for 10 minutes followed by right temporal cortex for 10 minutes.D. Sham (placebo) stimulation, using a modified coil, which produces no magnetic field but has an acoustic signature similar to that of an active coil, applied to left temporal cortex for 20 minutes.

The parameters (frequency, intensity and duration) of clinically useful rTMS have not yet been firmly established. The range of parameters described in the literature is diverse. The parameters in this study are based upon those found to be effective in reducing auditory hallucinations by Hoffman et al. The study parameters are all within the limits recommended by the international safety guidelines for rTMS.

Outcome measures:A second (or more) psychiatrist(s) who is blind to their experimental allocation will assess the level of auditory hallucinations experienced by all subjects. A description of the measurements to be made, and a timetable for these, is given below. Prior to commencing the main study, a pilot period will allow reliability to be checked and established. Each subject is assessed over a 25 week cycle. rTMS sessions take place in the weeks designated 0 and +1.

Analyses:The data obtained will be subject to a primary intention to treat analysis. A secondary per-protocol analysis will also be undertaken. The two main comparisons in the primary analysis will be:1. Left rTMS versus control (A+C versus B+D).2. Active rTMS versus sham (A+B+C versus D).

A repeated measures analysis with a random effects model will be used to test the significance of the between groups comparisons. Before and after within group comparisons will also be made and tested.

In addition to these continuous measures, outcomes will also be analysed in dichotomous terms. The main a priori dichotomous outcome will be defined as a 50% reduction in baseline auditory hallucinations as measured by the visual analogue scale. Rational post-hoc analysis of dichotomous outcomes will be permitted.

Estimates of the true magnitude of differences in the comparisons, and of the relative event rate for a positive outcome, will be calculated using confidence intervals for the differences between means and for proportions.




You can take part if:



You may not be able to take part if:


1. Organic brain disorder2. Previous documented unconsciousness3. Unstable coronary heart disease4. Contra-indications to rTMS, e.g. history of fits, recent cerebro-vascular accident, history of epileptic seizures, metal implants, cardiac pacemakers


Below are the locations for where you can take part in the trial. Please note that not all sites may be open.

  • Academic Department of Psychiatry
    The Longley Centre Norwood Grange Drive
    Sheffield
    S5 7JT

This information has not yet been provided by the study team. You'll have an opportunity to discuss any risks and benefits that may be associated with this study prior to consenting to taking part.

Dr Michael Hunter
+44 (0)114 2716231
m.d.hunter@shef.ac.uk



The study is sponsored by Department of Health (UK) and funded by Sheffield Health and Social Research Consortium (UK).



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Read full details for Trial ID: ISRCTN72210184
Last updated 27 October 2016

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