Prescribing the Right Agent for Depression in Adults (PRADA): a Double-blind, Randomised Controlled Trial Using a Web-based Multi-modal Clinical Decision Support System and Genetic Information to Personalise Antidepressant Treatment in Diverse Clinical Settings Across the Globe (PRADA)

August 27, 2026 updated by: University of Oxford
Depression is a common mental health problem affecting almost 300 million people worldwide. Antidepressants are recommended as one of the first line treatments for people with moderate-to-severe symptoms of depression. In our recent trial, PETRUSHKA, on the acute treatment of depression, we demonstrated that the PETRUSHKA Tool, an evidence-based shared decision support system to personalise antidepressant treatment, in comparison with usual care reduced by almost 40% the number of participants stopping their antidepressant early, also improving their depression and anxiety symptoms. To identify the best treatment for each individual, the PETRUSHKA Tool used clinical and demographic predictors. Pilot data show that genetic information can aid stratification of people experiencing depression and better target their treatment. Genetic data can be collected using low-cost DNA-sequencing technology in diverse clinical settings and low-resource environments. Hence, we hypothesised that individual-level pharmacogenomic information can further personalise antidepressant treatment. In this project called PRADA ("Prescribing the Right Agent for Depression in Adults"), we will develop and test in a global trial across Ethiopia, Pakistan and the UK, an evidence-based multimodal web-tool to help participants and clinicians choose the best pharmacological treatment for depression jointly, based on participant preferences and their individual clinical, demographic, cultural, and also genetic profile (PRADA Tool). We will compare the new tool with the PETRUSHKA Tool in a blind fashion, measuring adherence to antidepressant treatment, clinical response and quality of life over a 12-month follow-up.

Study Overview

Status

Not yet recruiting

Detailed Description

Major depressive disorder (MDD) is characterised by substantial heterogeneity in treatment response and tolerability. Although antidepressants are recommended as first-line treatment for moderate-to-severe depression, in routine care the selection of a specific antidepressant remains largely empirical.

As a result, many patients discontinue treatment prematurely due to lack of efficacy, or the presence of intolerable side effects. This limits the overall effectiveness of pharmacological interventions.

Our previous trial PETRUSHKA, an international, multicentre randomised controlled trial (RCT), addressed this challenge by developing and evaluating a web-based clinical decision-support system that integrated clinical and demographic predictors with participant preferences to personalise antidepressant selection and treatment. We demonstrated that antidepressant treatment can be optimised for individuals by using socio-demographic and clinical predictors, and patient preferences.

Recent studies have shown the beneficial role of pharmacogenomics to improve antidepressant response and reduce adverse effects in patients with MDD. In 2023, the Clinical Pharmacogenetics Implementation Consortium provided updated guidelines for choice and dosage of SSRIs and SNRIs based on genotypes at CYP2D6, CYP2C19, and CYP2B6 variants. Notably, pharmacogenetic variants have been studied extensively across global populations, in which they have similar influences but different frequencies between ancestry groups. Polygenic scores (PGS), while not diagnostic per se, can also contribute useful information about risk. Advanced but economical DNA sequencing technologies now exist, suitable for use in low resource environments, returning results in as little as 48 hours. Hence, pharmacogenomic variants and PGS can provide timely individual-level information, especially about adverse effects and genetic vulnerability for depression, that can be used to further personalise treatments and empower patients in the management of their symptoms . Moreover, genetic data could help identify patient subgroups with specific molecular characteristics associated with clinical features, that can also inform animal model studies and ultimately support drug discovery in neuroscience.

The PRADA trial builds directly on the PETRUSHKA framework by evaluating an enhanced, multimodal clinical decision-support system that incorporates also pharmacogenomic information (the PRADA Tool), compared to a system based only on clinical and demographic factors and patient preferences (the PETRUSHKA Tool). The trial is aimed to determine whether the PRADA tool can further improve personalisation of antidepressant treatment, improving its acceptability and clinical outcomes.

Both the PRADA Tool and the PETRUSHKA Tool employ bespoke algorithms in the back end to identify the best antidepressant for each individual participant. The algorithms: (a) are based on prediction models which use a combination of advanced analytics (statistics) and machine learning methods (artificial intelligence); (b) use a dataset which is a combination of real-world data (QResearch: https://www.qresearch.org/) from over 1 million primary care patients with depression in England and Wales, and individual participant data from approximately 40,000 participants recruited in randomised controlled trials; (c) incorporate preferences from participants, and clinicians (especially about adverse events); (d) generate a ranked list of personalised treatment recommendations that will inform the clinical discussion between clinicians and participant, and the final treatment decision. The difference between the PRADA Tool and the PETRUSHKA Tool is that the PRADA Tool will also use pharmacogenomic information and more personalised preferences about efficacy (i.e., specific clusters of symptoms participants want to target) and tolerability (i.e., specific adverse events participants would like to avoid).

To maintain the double-blind nature of the trial, all participants (irrespectively of whether they are randomised to the PRADA Tool, or the PETRUSHKA Tool) and clinicians will see and interact with an identical interface, available as the same web-based application and accessible from any computer, smartphone, or tablet. This single interface for all participants will be used to collect participants' preferences and present the list of recommended treatments to participants and clinicians. All participants will be asked the same questions in the tool frontend and all participants will have their genetic data analysed. The pharmacogenetic data and symptom prioritisation will be used in selecting the antidepressant only for participants randomised to the PRADA Tool and will not be used for the participants randomised to the comparator tool. The pharmacogenetic data will not be disclosed to participants or clinicians via the tool or at any other stage of the trial.

Additional blood samples will be collected at screening from all participants and these will be processed and used for downstream exploratory research in ethically approved studies, or transferred to an HTA licenced biobank.

Participants from the UK and Pakistan will also be offered the opportunity to take part in a sub-study at week 8 focussing on the delivery Polygeneic Scores (PGS). The aim of the Polygeneic Score delivery component of the trial is to compare two methods of delivering genetic test results about depression and evaluate whether the addition of genetic counselling, alongside the report and genetic information provided, impacts participants' empowerment. Using a factorial design, participants in both arms will be individually randomised to receive either: (a) a written report on their customised PGS for depression, accompanied by tailored material explaining how to interpret this information; or (b) the same written report and tailored material, plus a one-to-one session (delivered remotely or face to face) with a genetic counsellor to discuss and explain the results.

Participants in the UK only will also have the opportunity to take part in two other sub-studies; a microbiome sample collection and sensor data collection. For the microbiome study, participants will be asked if they wish to provide stool samples for gut microbiome profiling and the completion of questionnaires related to diet and digestion three times during the PRADA trial ( screening to week 24). At the end of the sub-study, they will receive a digital report of their microbiome data.

Particpants in the UK may opt to take part in a sensor data collection using the mindLAMP mental health platform. The aim of this sub-study is to explore whether passively-collected smartphone data can be used to derive longitudinal behavioural markers relevant to depression, including mobility, routine regularity, and activity levels. The sub-study will last 8 weeks from baseline and particpants will be asked to complete a short daily questionnaire via the mindLAMP app. Following completion of data collection, the participant will receive a digital personalised summary report describing behavioural patterns observed during the study period.

Study Type

Interventional

Enrollment (Estimated)

2142

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion criteria:

  1. Aged 18-74 years inclusive;
  2. Willing and able to give informed consent for participation in the trial;
  3. Clinical primary diagnosis of major depressive episode, for which an antidepressant is clinically indicated;
  4. PHQ-9 score of at least 10;
  5. Willing and able to start antidepressant treatment as monotherapy;
  6. Able to understand and answer self-administered questionnaires in their local language.

Exclusion Criteria

  1. Taken an antidepressant in the preceding 4 weeks at a therapeutic dose;
  2. Current or historical diagnosis (lifetime) of ADHD, bipolar disorder, dementia, mania/hypomania, psychosis/schizophrenia
  3. Current or historical diagnosis (within 10 years) of any eating disorders, PTSD, OCD or alcohol/substance use disorder
  4. Treatment Resistant Depression (i.e., having tried 2 or more antidepressants for the same depressive episode at adequate dose and time);
  5. Known diagnosis of arrhythmias (including Q-T prolongation, heart block), recent myocardial infarction (within 5 years), difficult-to-treat epilepsy, acute porphyrias;
  6. Requires urgent mental care or admission (including suicidal intent/plans);
  7. Concurrently enrolled in another investigational medicinal product (IMP) trial that, in the opinion of the investigator, is likely to interfere with the PRADA trial or an interventional trial about depression;
  8. Pregnant, planning pregnancy or lactating (self-reported);
  9. Unable to give blood sample for genetic analysis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PRADA Tool

A web-based clinical decision-support system for participants and clinicians to enable personalised antidepressant treatment decision-making, using clinical and demographic predictors, pharmacogenomic information and individual preferences about adverse events.

At week 8, participants who consent to the optional Polygenic Score (PGS) sub-study will be randomised to receive either the Polygenic Score (PGS) material alone, or Polygenic Score (PGS) material with psychiatric genetic counselling (1:1, factorial)

The PRADA Tool will incorporate a personalised evidence-based prediction model based on participants' demographic and clinical characteristics, their individual preferences on adverse events and specific symptom clusters, and information about their pharmacogenetic profile. The tool will be delivered at the baseline visit. Once particpants have provided their preferences on adverse events and symptom clusters, the participant and clinician will then choose one antidepressant from a personalised list of ranked antidepressants.
Active Comparator: PETRUSHKA Tool

A web-based clinical decision-support system to enable personalised antidepressant treatment decision-making, using clinical and demographic predictors, and individual preferences about adverse events, but not pharmacogenomic information.

At week 8, participants who consent to the optional Polygenic Score (PGS) sub-study will be randomised to receive either the Polygenic Score (PGS) material alone, or Polygenic Score (PGS) material with psychiatric genetic counselling (1:1, factorial)

The PETRUSHKA Tool use participants' demographic and clinical characteristics together with individual preferences on adverse events to personalise antidepressant treatment. To preserve the blinding, the PETRUSHKA Tool used in the PRADA Trial has been modified to collect pharmacogenetic data and preferences on symptom clusters, but this information will not be used at all to inform decisions in the PETRUSHKA Tool. The tool will be delivered at the baseline visit. Once particpant has provided their preferences on adverse events and symptom clusters, the participant and clinician will then choose one antidepressant from a personalised list of ranked antidepressants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
All-cause treatment discontinuation
Time Frame: Baseline to week 8
To determine whether using the PRADA Tool to "personalise" antidepressant treatment, results in an increased proportion of participants continuing the allocated treatment, compared to the PETRUSHKA Tool.
Baseline to week 8

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

October 1, 2028

Study Registration Dates

First Submitted

August 27, 2026

First Submitted That Met QC Criteria

August 27, 2026

First Posted (Actual)

September 1, 2026

Study Record Updates

Last Update Posted (Actual)

September 1, 2026

Last Update Submitted That Met QC Criteria

August 27, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 365942
  • 303135/Z/23/Z (Other Grant/Funding Number: Wellcome)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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