Psychological aspects of taking part in a clinical trial

Why does joining a clinical trial affect your emotions?

Taking part in a cancer clinical trial is often described by patients and caregivers as a source of psychological distress and emotional activation. It is not only a medical decision^[1]. An analysis of patient and caregiver posts about clinical trials found that fear, sadness, trust and anticipation were the most prevalent emotions expressed. Both positive and negative sentiments were reported at high levels within the same group of people. This shows that hope and worry commonly coexist rather than replacing one another^[2]. This coexistence matters: you do not have to choose between feeling optimistic about a new treatment and feeling anxious about its uncertainties. Both reactions can be present, valid, and worth mentioning to your care team at the same time^[1].

This emotional load is described as a normal part of the decision-making process. It is not a sign that something is going wrong with the trial or with you. Understanding which feelings are common at which stage can help you recognise your own reactions and know what to raise with the research team. Many people entering a trial have never had to weigh up unfamiliar concepts such as randomisation, blinding or experimental dosing. At the same time, they must cope with a serious diagnosis. The combination of medical uncertainty with emotional strain is itself part of what researchers try to measure and support^[1].

Who tends to feel more comfortable about joining a trial?

A study of 100 people invited to join a clinical trial found that those who agreed to take part scored significantly higher on self-efficacy, social support and curiosity. They also scored significantly lower on anxiety and fear of negative evaluation, compared with those who declined. Patients who agreed to participate were also significantly younger than those who refused. No differences were found by sex, employment status, monthly income or education level^[3].

These findings do not mean that anxious or less socially supported patients cannot or should not take part. They show that your own psychological starting point shapes how comfortable the decision feels. This includes how supported you feel and how confident you are in coping with adversity. It can also guide what kind of support you ask for from the research team before you consent. Recognising that curiosity and a sense of being able to influence your own situation are linked with a more comfortable decision does not mean people who feel frightened or unsupported are unsuited to research. It simply points to areas where additional support could make the process feel less daunting. These might include arranging extra explanation sessions or involving a family member in consent discussions^[3].

Which psychological traits were measured, and how did they differ?

Psychological measure	Pattern found in patients who agreed to participate
Self-efficacy (total score, effectiveness in adversity, initiation and persistence)	Significantly higher (p<0.001)[3]
Social support (family, friendship, social activities satisfaction, intimacy)	Significantly higher (p<0.001, p=0.015, p=0.002)[3]
Curiosity (absorption, exploration)	Significantly higher (p<0.001)[3]
State and trait anxiety	Significantly higher in patients who refused (p<0.001)[3]
Fear of negative evaluation, social avoidance and distress	Significantly higher in patients who refused (p<0.001)[3]

Taken together, this pattern suggests that participation decisions are shaped as much by a person's psychological resources as by the clinical details of the trial itself. A patient with strong family support and a habit of approaching new situations with curiosity may find the same trial proposal far less threatening than someone facing high baseline anxiety and little social backing. This can happen even when both are offered identical information about the study^[3].

What emotions can you expect at each stage of a trial?

The emotional experience of a trial is not the same from consent to follow-up; different worries tend to surface at different points. The table below groups psychological themes reported in patient, caregiver and staff studies by the stage of the trial where they most often arise.

Trial stage	Commonly reported psychological themes	Source
Deciding whether to take part / giving consent	Fear, anticipation, hope, curiosity about the study; adolescents in one trial often agreed for reasons described as "conditional altruism" – wanting to help future patients as well as themselves	[4]
Understanding random treatment allocation	Consent often given with limited understanding of randomisation and of the difference between treatment arms	[4]
Being told which treatment group you are in	Staff describe having to prepare for and manage patient disappointment and anger at the moment of treatment allocation	[5]
During treatment and follow-up	Sadness, trust, anticipation; mix of positive and negative sentiment reported at similarly high levels	[2]
Looking back after finishing the trial	Most adolescent participants reported being largely positive about their overall experience	[4]

Seeing these stages laid out separately can be reassuring in itself. A patient who feels calm during the consent conversation but suddenly anxious on the day of treatment allocation is following a documented pattern. The same is true for someone who feels confident throughout treatment but reflective and uncertain once follow-up ends. Neither is experiencing something unusual compared with other participants^[4].

How does not knowing your treatment group affect how you feel?

Many trials use randomisation, where a computer-based process decides by chance which treatment group you join, and blinding, where you and sometimes your doctor do not know which treatment you are receiving. One listed risk of taking part in clinical research is being randomly assigned to receive a standard treatment or a placebo, an inactive substance with no active treatment effect^[6].

In a study of adolescents in a mental health trial, participants often consented without a strong understanding of the difference between treatment arms or of how the randomisation process worked. This gap between what is explained and what is understood can add uncertainty on top of the illness itself. If you are unsure what randomisation or blinding means for your specific trial, ask the research team to explain it again in your own words before you sign the consent form. Repeating the explanation back to a member of staff, or asking them to draw a simple diagram of how the treatment groups work, is a practical way of closing this gap. This can be done before uncertainty has a chance to grow into ongoing worry^[4].

Research staff involved in delivering trials have described the moment of revealing which group a patient has been allocated to as one of the most emotionally demanding parts of their own role. It requires them to prepare in advance for a patient's possible disappointment or anger. This shows that the emotional weight of allocation is recognised on the professional side too, and that staff are generally trained to expect and respond to it. Knowing that this moment is anticipated and planned for by the team, rather than an unscripted or awkward surprise, can make it easier to voice disappointment openly. There is no need to hide such feelings out of politeness^[5].

How do caregivers experience a loved one's participation in a trial?

Caregivers of patients considering or taking part in a cancer clinical trial report emotional activation alongside the patients themselves. This is expressed through shared experiences, requests for advice, and a mix of both on social platforms^[1]. In one analysis of 241 posts about clinical trials, 112 were written by caregivers compared with 129 by patients, and fear, sadness, trust and anticipation were prominent in both groups^[2]. The near-equal split between patient and caregiver voices in this analysis is itself informative. It indicates that caregivers are not a silent audience to the decision but active participants in processing its emotional weight. They often search for reassurance and practical advice in much the same way patients do^[1].

If you are supporting someone through a trial, it is worth naming your own emotional reactions rather than treating them as secondary to the patient's. You can ask the research team whether they offer any information or contact point specifically for caregivers, separate from the patient's own consultations. Caregivers who feel able to voice their own fear or sadness, rather than suppressing it to appear strong for the patient, may find it easier to sustain the practical and emotional support role. This matters over the full length of a trial^[2].

What support can you expect from the research team during a trial?

Every trial has an investigator, a doctor responsible for the clinical conduct of the study and for the safety of participants at that site. You will be told about relevant risks before you decide to take part, and you can stop taking part at any time without having to give a reason^[7].

Care from a research team that includes doctors and other health professionals familiar with advanced treatments is described as one of the recognised benefits of taking part in clinical research^[6]. In some settings, patients taking part in a trial because they are unwell have reported better clinical outcomes, linked to a higher level of contact and monitoring throughout the study. This closer level of contact, involving more frequent appointments and check-ins than standard care, can itself function as a form of psychological support. Patients are less likely to feel left to cope with symptoms or side effects on their own between visits^[7].

Digital tools such as smartphone apps are increasingly used alongside in-person visits to track symptoms and wellbeing between appointments, giving the clinical team more real-time information about how a patient is coping. These tools are intended to support, not to replace, direct contact with your healthcare professional, and their use should be agreed between you and your clinician^[8].

How common is emotional difficulty during cancer treatment involving research?

In a real-world study of 1,450 patients with solid tumours receiving systemic therapy, the median emotional functioning score was 66.7 on a scale of 0 to 100, where lower scores indicate a worse emotional state. Women, younger patients under 62.5 years, and those receiving palliative rather than curative treatment tended to report worse emotional functioning than men, older patients and those undergoing curative treatment. These differences suggest that certain groups of patients may benefit from proactively being asked about their emotional wellbeing rather than waiting for them to raise it. Younger age or a palliative treatment goal appear to be linked with a higher likelihood of emotional difficulty during systemic therapy^[8].

Depressive symptoms and other psychological issues in cancer care are usually assessed using standardised, validated questionnaires, generally completed during a visit to the relevant healthcare professional. If you notice persistent low mood, sadness or anxiety during a trial, this is a recognised and measurable part of many patients' experience. It is not something unusual to hide from your care team. Bringing up these feelings during a routine questionnaire or appointment, rather than waiting for a crisis point, gives the team the earliest possible opportunity to offer additional psychological support alongside your ongoing treatment^[8].

What do participants say about the experience once the trial is over?

In a qualitative study of 76 adolescents interviewed after completing therapy within a randomised controlled trial for depression, the large majority found participation in the trial acceptable, and most described their overall experience in positive terms. The same study raised an open question about whether taking part in the research elements of a trial may itself influence clinical outcomes, separately from the treatment being tested. This includes elements such as extra assessments or the awareness of being observed^[4].

This suggests that the experience of being cared for within a structured research process can be a meaningful, positive part of a trial in its own right, alongside whatever treatment effect is being studied. Many participants described the sense of being closely followed, regularly asked about their wellbeing, and given more attention than they might have received outside a trial. They valued this independently of which treatment arm they had been assigned to^[4].

When should you speak to the study team or your doctor about how you are coping?

Speak to the research staff or your doctor if you experience unwanted side effects affecting your health, if you find it difficult to manage complex medication doses, or if you feel the treatment is not helping you or is affecting your mood in a way that concerns you^[6]. You are entitled to discuss any concern with the research staff or with your doctor at any point during the trial^[7].

• If you feel persistently low, anxious or distressed about being in the trial, tell the research nurse or investigator – this is part of what they monitor^[7].
• If you do not understand which treatment group you are in, or why, ask for the explanation again – participants have reported consenting without fully grasping randomisation^[4].
• If you are a caregiver feeling overwhelmed, ask whether the study team has any separate information or contact point for caregivers^[1].
• You can withdraw from the trial at any time without giving a reason, and this decision does not affect your right to standard care^[7].

Keeping this list close at hand, whether written down or saved on a phone, can make it easier to raise a concern in the moment. This is often easier than trying to remember it later during a busy clinic appointment^[7].

Summary

Feeling fear, sadness, hope and anticipation at different points of a clinical trial is a documented and common experience for both patients and caregivers. It is not a sign that something has gone wrong with the study or with you^[1]. Knowing which reactions tend to appear at consent, at treatment allocation, during follow-up and after the trial ends can help you recognise your own responses. It can also help you put them into words when you talk to the research team^[2].

The research staff looking after you are there to explain risks, answer questions about randomisation or your treatment group, and support you emotionally as well as clinically throughout the study. Raising a psychological concern with your investigator, research nurse or doctor is a normal and expected part of taking part in a trial, at any stage, for as long as you remain enrolled^[7].

This article is for general information only and does not replace advice from your doctor or the research team responsible for your trial. Always discuss your specific situation, symptoms or concerns directly with them.

1. [1] Chichua M, Filipponi C, Mazzoni D, Pravettoni G. The emotional side of taking part in a cancer clinical trial. PLoS One. 2023;18(4):e0284268. doi:10.1371/journal.pone.0284268 (accessed 2 June 2026) – https://pmc.ncbi.nlm.nih.gov/articles/PMC10124833/
2. [2] Chichua M, Filipponi C, Mazzoni D, Pravettoni G. The emotional side of taking part in a cancer clinical trial. PLoS One. 2023;18(4):e0284268. doi:10.1371/journal.pone.0284268 (accessed 2 June 2026) – https://pubmed.ncbi.nlm.nih.gov/37093865/
3. [3] Gouveia R, Tedim Cruz V, Almeida L. Sociodemographic and psychological characteristics influencing patients' willingness to participate in clinical trials. BMJ Open Qual. 2022;11(4):e002044. doi:10.1136/bmjoq-2022-002044 (accessed 2 June 2026) – https://pmc.ncbi.nlm.nih.gov/articles/PMC9628668/
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5. [5] Lawton J, Kirkham J, White D, Rankin D, Cooper C, Heller S. Uncovering the emotional aspects of working on a clinical trial: a qualitative study of the experiences and views of staff involved in a type 1 diabetes trial. Trials. 2015;16:3. doi:10.1186/1745-6215-16-3 (accessed 2 June 2026) – https://pmc.ncbi.nlm.nih.gov/articles/PMC4326295/
6. [6] What are the risks and benefits of participating in clinical research? (accessed 2 June 2026) – https://www.nimh.nih.gov/news/media/2021/what-are-the-risks-and-benefits-of-participating-in-clinical-research
7. [7] Celebrating the superpower of Clinical Trials (accessed 2 June 2026) – https://www.kentmedwaymentalhealth.nhs.uk/news-and-events/news/celebrating-the-superpower-of-clinical-trials/
8. [8] Is it time to shift supportive care toward digital-assisted approaches? (accessed 2 June 2026) – https://dailyreporter.esmo.org/esmo-congress-2025/ai-digital-oncology/is-it-time-to-shift-supportive-care-toward-digital-assisted-approaches