PAX-D
Research type
Research Study
Full title
PAX-D: Randomised placebo-controlled trial evaluating the efficacy and mechanism of pramipexole as add-on treatment for people with treatment resistant depression
IRAS ID
253702
Contact name
Michael Browning
Contact email
Sponsor organisation
University of Oxford / Clinical Trials and Research Governance
Eudract number
2019-001023-13
ISRCTN Number
ISRCTN84666271
Duration of Study in the UK
3 years, 4 months, 31 days
Research summary
PAX-D is comparing a medicine called pramipexole with placebo for Treatment Resistant Depression (TRD) ie. depression that has not responded to current antidepressant medicines and/or psychological therapies. Pramipexole is licensed for Parkinson’s Disease and Restless Leg Syndrome.
TRD affects between 20% and 30% of people taking treatment for depression and is both a leading cause of suffering to individuals and costly to society in terms of, for example, working days lost. There is some evidence that pramipexole may be effective for TRD when added to current antidepressant treatment but more rigorous evaluation is needed.
Pramipexole works in a different way to conventional antidepressant medicines and may be effective in treating lack of motivation which is a key symptom of depression. In addition to assessing the effectiveness, safety and tolerability of pramipexole in the short-term (12 weeks) and longer-term (48 weeks), PAX-D will measure motivation over the first few weeks of treatment.
PAX-D is open to people who meet criteria for TRD (non-response to at least 2 courses of antidepressant medicines), are willing to continue an antidepressant medicine in addition to pramipexole or placebo, to attend a psychiatric clinic and to complete regular ratings that will indicate the effects of allocated medication. Some ratings will be completed online and some with a researcher over the phone.
Participants will be in the trial for about 50 weeks: 2 weeks pre-treatment to familiarise themselves with rating procedures and 48 weeks on allocated treatment. During the 48 weeks neither they nor their clinicians will know whether they have been allocated pramipexole or placebo. Blood samples will be taken at the start of the pre-treatment period and participants will be asked to attend a minimum of six clinic visits for the trial. At three of those visits they will be asked to complete a simple computer game.
REC name
South West - Central Bristol Research Ethics Committee
REC reference
19/SW/0216
Date of REC Opinion
1 Nov 2019
REC opinion
Favourable Opinion