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RADAR Trial: Testing the effects of reducing and discontinuing antipsychotic medication in people with long-term schizophrenia and similar conditions

Research into Antipsychotic Discontinuation and Reduction (RADAR): a randomised controlled trial

Status
Active, not recruiting
Phases
Unknown
Study type
Interventional
Source
ISRCTN
Registry ID
ISRCTN90298520
Enrollment
218
Registered
2017-02-07
Start date
2017-03-24
Completion date
Unknown
Last updated
2026-05-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia Mental and Behavioural Disorders Schizophrenia

Interventions

Consenting participants are randomly allocated to one of two groups. Control group: Participants continue to receive antipsychotic treatment at the original dose. Intervention group: Participants ta

Sponsors

University College London
Lead Sponsor
North East London NHS Foundation Trust
Collaborator

Eligibility

Sex/Gender
All
Age
18 Years to 110 Years

Inclusion criteria

Inclusion criteria: 1. Aged over 18 years 2. A clinical and/or ICD10 diagnosis of schizophrenia, schizoaffective disorder, delusional disorder or other non-affective psychosis 3. More than one previous episode of relapse or psychotic exacerbation, or a single episode lasting more than one year 4. Taking antipsychotic medication

Exclusion criteria

Exclusion criteria: 1. Participant lacks capacity to consent to the trial 2. Participant has insufficient command of spoken English to understand trial procedures 3. Participant subject to a Community Treatment Order (CTO) that includes a requirement to take antipsychotic medication 4. Clinician considers there will be a serious risk of harm to self or others 5. Participant has been admitted to hospital or had treatment from the Home Treatment or Crisis Team within the last month 6. Females who have a confirmed pregnancy 7. Females who are breast-feeding 8. Involvement in another IMP trial 9. No contraindications to continuing on antipsychotic medication

Design outcomes

Primary

MeasureTime frame
Social functioning is measured by the Social Functioning Scale at baseline, 6, 12 and 24 months Added 14/09/2022: Also measured between 48-84 months from randomisation into the original trial

Secondary

MeasureTime frame
1. Symptoms are measured by the Positive and Negative Syndrome Scale (PANSS) at baseline, 6, 12 and 24 months 2. Side effects as measured by the Modified Glasgow Antipsychotics Side-effects Scale (GASS) at baseline, 6, 12, and 24 months 3. Patient satisfaction as measured by the Client Satisfaction Questionnaire (CSQ 8) at baseline, 6, 12 and 24 months 4. Subjective quality of life as measured by the Manchester Short Assessment of quality of life (MANSA) at baseline, 6, 12 and 24 months 5. Neuropsychological function tests at baseline, 12 and 24 months 6. Medication adherence as measured by the Medication Adherence Rating Scale (MARS-5) at baseline, 6, 12 and 24 months 7. Relapse as measured by the relapse assessment schedule questionnaire at 6, 12 and 24 months 8. Health state as measured by the EQ-5D-5L at baseline, 6, 12 and 24 months 9. Wellbeing as measured by the ICECAP-A at baseline, 6, 12 and 24 months 10. Cost of health and social care as measured by the Client Service Receipt Inventory at baseline, 6, 12 and 24 months 11. Ability to work as measured by the Work Productivity and Activity Questionnaire at baseline, 6, 12 and 24 months 12. Economic data collected from patient records at baseline 12 and 24 months 13. Recovery as measured by the Questionnaire about the Process of Recovery (QPR) at baseline, 6, 12 and 24 months 14. Sexual experiences as measured by the Arizona Sexual Experiences Scale (ASEX) at baseline, 6, 12 and 24 months Added 14/09/2022: All outcome measures except the social cognition battery will also be measured between 48-84 months from randomisation into the original trial

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: May 16, 2026