Unfortunately due to the ongoing COVID-19 pandemic, we are currently having to pause recruitment for the BICBID study.

If you are interested in taking part then please do continue to register your interest below. We will add your details to our database and will contact you once we restart recruitment.

Thank you for your interest in the BICBID study (Blood Immune Biomarkers in Depression). You can read more details about the study below. If you are interested in taking part, you can register your interest on the form at the bottom of this webpage.


Purpose of the study

  • Many people with depression still feel depressed despite taking antidepressant medications. 
  • Scientific evidence has shown a link between inflammation and depression. We also know that stress alters the immune system, and that the immune system may be important in the link between stress and depression.
  • This study aims to develop a blood test which can identify how immune cells in the blood are altered in depression so that, in the future, we can offer people experiencing depression more personalized care and treatments, depending on their blood test results.
  • We aim to recruit approximately 30 people currently experiencing depression and 30 people who have never experienced depression to attend for a study visit.

Transmission electron micrograph of macrophage cells infected with Candida yeast spores. The Candida spores are visible in the bottom left cell. Macrophages are white blood cells of the immune system which engulf and destroy foreign material. They are found in all tissues of the body. Overgrowth of yeasts can result in fungal infections such as thrush (candidiasis). Horizontal image width is 33 microns.

What does this study involve? 

  • You will be asked to make one visit to the study site, which is on the Addenbrooke’s Hospital campus in Cambridge, UK.
  • You will have to fast overnight (10 hours) before the study visit.
  • At the visit, you will be asked questions about your mental health.
  •  You will provide blood and urine samples for various tests and undergo a heart trace recording (ECG).
  • You will also complete a short activity at home where you collect saliva samples so that we can measure your stress hormone levels. 

Potential benefits of taking part 

If you take part in the study visit you will receive £100 for your time and effort, plus your travel expenses.

Potential disadvantages of taking part

The questionnaires, blood sampling and other medical tests are low risk for your health.


Will I be eligible to take part? 

We are planning to study both people who are currently experiencing depression and people who have never experienced depression (the “control group” below). We have listed some of the key criteria below: 

  • Aged between 18 and 60 years inclusive 
  • Body mass index (BMI) between 18.0 and 36.0 
  • Not currently diagnosed with schizophrenia, bipolar disorder or an eating disorder
  • Not currently pregnant or breast-feeding
  • Not using recreational drugs other than tobacco and alcohol
  • To be eligible for the “control group”, you must never have been treated for a mental health condition.
  • To be eligible for the group experiencing depression, you need to be currently depressed. You will also need to be taking treatment with an antidepressant medication. This is simply because we need people in the study to be similar to each other in terms of the medications they are taking – we know that many people choose and benefit from non-pharmacological treatments for depression.
  • If you have other medical diagnoses, you may still be able to take part as long as these conditions are under control at the moment.

The Participant Information Sheet (embedded below) has a lot more detailed information on the study including details of the visit. Please read it through carefully before submitting your details.


BICBID Trial - Expression of Interest

  • If you are interested in learning more or think you might be suitable, please fill in the contact details form and a researcher will contact you. Please ensure you have read the participant information sheet before completing the contact form.

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