Information for GPs and Researchers


Trial Summary


Approximately 1 in 200 adults are recognised as having a learning disability. Illness in this population is high, including significant rates of challenging behaviour and mental illness. Use of psychoactive medication is high and there is particular concern over the use of anti-psychotic medication that is prescribed for reasons other than the treatment of psychosis. Control of challenging behaviour is the primary reason why such medications are prescribed despite the absence of good evidence for any therapeutic effect for this purpose. This problem is central to the intervention being evaluated in this trial.


The central research question to be addressed is whether anti-psychotic medication prescribed to adults with learning disabilities for the treatment of challenging behaviour can be withdrawn or reduced without behaviour or mental health deteriorating and treatment costs escalating.


A 2 arm randomised double-blind placebo-controlled non-inferiority withdrawal trial. Treatment will be primary care led and will be supported by a specially designed trial specific treatment and safety package. During the trial, those in the intervention arm will proceed through 4 monthly approximately 25% reduction stages within a 6 month period (although blinded, the GP has discretion to delay progression to the next step). The control group will maintain baseline treatment. Treatment achieved at 6 months will be maintained for a further 3 months under blind conditions. At 9 months, the blinding will be broken for clinicians and participants and medication changes monitored over the 12 month period from baseline.


We will recruit 310 adults with learning disabilities (LD) identified through practice LD registers prescribed one of two anti-psychotic drugs (risperidone or haloperidol) for treatment of challenging behaviour with no known current psychosis or previous recurrence of psychosis following prior drug reduction.

Duration and follow-up

Participants will be in the trial for 12 months. Assessments will be completed at 6, 9 and 12 months from randomisation.

Download our GP information flyer!

Trial Flowchart

Get involved!

Are you a GP or practice manager in South Wales or South West England? Would you like to be part of the ANDREA-LD trial?  We would be very grateful for your involvement, and you can help us even if you choose not to become a recruiting practice within the trial!

Click here to download our Practice Approach letter.

Click here to download our Staff Involvement document.

Contact Us

For more information, please contact the ANDREA-LD Trial Manager:

Ms. Elizabeth Randell

South East Wales Trials Unit

Cardiff University

Seventh Floor, Neuadd Meirionnydd

Heath Park 

Cardiff CF14 4YS

Or email the ANDREA-LD Trial:

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