what is the study about?
Recent studies suggest that the blood pressure medication losartan might have the potential to improve psychological treatments, and we hope that the knowledge gained from this study will eventually contribute to the improvement of treatment for people who experience emotional problems such as anxiety disorders. We would like to test two groups of people: one who receives a single, low dose of losartan, and one who receives placebo (a substance not containing any medication). Your allocation to one of these groups will be randomised. In particular, we are interested in how this drug affects emotional processing in the brain. To measure this, you will be working on a battery of computer tasks, responding to emotional and non-emotional stimuli. During some of these tasks, we will measure activation patterns in your brain using functional magnet resonance imaging (fMRI).
what does the study involve?
You will be asked to come to see us on two occasions.
1. Screening Visit
Your first visit will be a screening session where we will make sure that it is safe for you to take part, and that you are suitable for this particular study. We will also give you the chance to ask any questions you might have. This session will involve asking you to: sign a consent form, give us some information about your medical history, answer some detailed questions about your current and previous psychological well-being, complete a series of questionnaires asking about symptoms such as anxiety or low mood. The screening visit will take about 1 hour.
2. Testing Visit
We will ask you to have your last meal two hours before this visit. At the beginning of your visit, you will receive a capsule that will either be a placebo capsule (not containing any medication; main ingredient: microcrystalline cellulose), or a 50mg losartan capsule. The treatment that you will be allocated to receive will be chosen at random, and neither you nor the researcher will be aware which treatment you have received. Losartan has been tested in similar studies before, and it has been shown that single-doses like the one you might be receiving are unlikely to cause any side effects. We will measure your blood pressure and heart rate before and after having taken the capsule. One hour after having taken the capsule, we will ask you to take part in the fMRI scan. To undergo magnetic resonance scanning you would be asked to lie still on a table inside the MRI scanner. The scan will take about 45mins and we will ask you to respond via a button box to a Memory Task displayed on a screen that you can see whilst in the scanner. In this task, we will present images that you will be asked to categorise, using a left key for animals and a right key for landscapes. In a later test, we will find out how well you remember these images outside the scanner. While you are in the scanner, we may measure your breathing, heart rate, and the electrical characteristics of your skin. This will involve putting a band around your chest, and wearing a clip on one of your fingers. After the scan, we will ask you to complete some more tasks on a computer laptop.The total time of this visit is approximately 3 ½ to 4 hours.
You will be reimbursed £50 for your time and travel.
1. Screening Visit
Your first visit will be a screening session where we will make sure that it is safe for you to take part, and that you are suitable for this particular study. We will also give you the chance to ask any questions you might have. This session will involve asking you to: sign a consent form, give us some information about your medical history, answer some detailed questions about your current and previous psychological well-being, complete a series of questionnaires asking about symptoms such as anxiety or low mood. The screening visit will take about 1 hour.
2. Testing Visit
We will ask you to have your last meal two hours before this visit. At the beginning of your visit, you will receive a capsule that will either be a placebo capsule (not containing any medication; main ingredient: microcrystalline cellulose), or a 50mg losartan capsule. The treatment that you will be allocated to receive will be chosen at random, and neither you nor the researcher will be aware which treatment you have received. Losartan has been tested in similar studies before, and it has been shown that single-doses like the one you might be receiving are unlikely to cause any side effects. We will measure your blood pressure and heart rate before and after having taken the capsule. One hour after having taken the capsule, we will ask you to take part in the fMRI scan. To undergo magnetic resonance scanning you would be asked to lie still on a table inside the MRI scanner. The scan will take about 45mins and we will ask you to respond via a button box to a Memory Task displayed on a screen that you can see whilst in the scanner. In this task, we will present images that you will be asked to categorise, using a left key for animals and a right key for landscapes. In a later test, we will find out how well you remember these images outside the scanner. While you are in the scanner, we may measure your breathing, heart rate, and the electrical characteristics of your skin. This will involve putting a band around your chest, and wearing a clip on one of your fingers. After the scan, we will ask you to complete some more tasks on a computer laptop.The total time of this visit is approximately 3 ½ to 4 hours.
You will be reimbursed £50 for your time and travel.
what IS losartan?
Losartan is a medication for high blood pressure which has had UK market authorisation for 20 years. Recent research suggests that this drug can also improve cognition and the effects of learning experiences. As a side effect, some participants experience symptoms such as drowsiness, muscle weakness, low blood sugar, headaches, hypotension or allergic reactions. However, if you are randomised to the losartan condition you will only be asked to take a very low, single dose. Recent studies have shown that taking such doses is very unlikely to cause side effects. If you nevertheless experience once of these severe side effects, you will be withdrawn from the study.
exclusion and inclusion criteria
We are looking for healthy participants aged 18-50. You may not be able to take part if you:
* have a Body mass Index below 18 or over 30
* have insufficient English skills
* are smoking more than 5 cigarettes a day
* are pregnant or breast-feeding
* have been on certain medication that influences the central nervous system (e.g. antidepressants) during the last 6 weeks
* are currently taking blood pressure or other heart medication, especially a drug called aliskiren, or beta blockers
* are currently diagnosed with intravascular fluid depletion
* have ever had a psychological disorder such as severe depression, bipolar disorder, eating disorder, psychotic disorder, alcohol or substance abuse
* have a close family member with a history of a severe psychiatric disease
* have a history of epilepsy or another neurological disorder, or other severe diseases such as kidney, liver, heart or respiratory problems, renal insufficiency, or systemic infection
* participated in another study involving certain medication during the last 6 weeks
Please do not hesitate to contact us if you are unsure whether you are eligible.
* have a Body mass Index below 18 or over 30
* have insufficient English skills
* are smoking more than 5 cigarettes a day
* are pregnant or breast-feeding
* have been on certain medication that influences the central nervous system (e.g. antidepressants) during the last 6 weeks
* are currently taking blood pressure or other heart medication, especially a drug called aliskiren, or beta blockers
* are currently diagnosed with intravascular fluid depletion
* have ever had a psychological disorder such as severe depression, bipolar disorder, eating disorder, psychotic disorder, alcohol or substance abuse
* have a close family member with a history of a severe psychiatric disease
* have a history of epilepsy or another neurological disorder, or other severe diseases such as kidney, liver, heart or respiratory problems, renal insufficiency, or systemic infection
* participated in another study involving certain medication during the last 6 weeks
Please do not hesitate to contact us if you are unsure whether you are eligible.
materials
| participant_information_sheet_v2_121218_clean.pdf |
contact
Please get in touch if you would like to take part in this study, and do not hesitate to also let us know if you have any questions or worries about your participation.
Theodora Thoroddsen
DPhil student
Email: theodora.thoroddsen@psych.ox.ac.uk
Theodora Thoroddsen
DPhil student
Email: theodora.thoroddsen@psych.ox.ac.uk
