The RADAR trial: methods and results

Maria LONG1,5, Joanna MONCRIEFF1,5, Stefan PRIEBE3, Nadia CRELLIN1,4, Jacki STANSFELD1,5, Ruth COOPER1,2, Nicola MORANT1

1University College London, London, United Kingdom
2Kings College London, London, United Kingdom
3Queen Mary University of London, London, United Kingdom
4Nuffield Trust, London, United Kingdom
5North East London Foundation NHS Trust (NELFT), London, United Kingdom

Introduction

Long-term antipsychotic treatment is the standard treatment for people diagnosed with schizophrenia and similar, recurrent psychotic conditions. It has been shown to reduce rates of relapse but most trials involve abrupt discontinuation. Antipsychotic medication also has significant side effects so minimising unnecessary exposure is important. The RADAR trial was a randomised trial set up to evaluate the effects of gradual reduction of antipsychotic medication compared to maintenance treatment. The trial included qualitative studies of participants’ and carers' experience of the antipsychotic reduction process, and had a Lived Experience advisory panel. This presentation sets out the main results of the study as context for the lived experience aspects of the trial.

Methods

The RADAR trial consisted of a randomised, open trial comparing gradual antipsychotic reduction to maintenance treatment in people diagnosed with schizophrenia and related conditions. The primary outcome was social functioning. Relapse, symptoms, quality of life and other outcomes were assessed. The final follow-up was at two years. Assessments and analysis were conducted blind.

Results

The trial enrolled 253 participants. Results showed relapse rates were higher in the reduction group compared to the maintenance group, with no differences in social functioning or other outcomes. However, only a minority of people who reduced or stopped antipsychotics relapsed. New data on the relationship between relapse and social functioning will be presented.

Discussion

Results were consistent with other studies that show increased risk of relapse following reduction and discontinuation of antipsychotics over the short-term. No benefit of antipsychotic reduction was shown in the current trial. The trial results can inform people’s decisions about whether to take or continue on long-term antipsychotic treatment. A long-term follow-up is in process.