Internet-delivered cognitive behavioural therapy (iCBT) with main carer access for depression and anxiety among breast cancer survivors

INTERVENTION: Informed consent, screening questionnaire assessing inclusion and exclusion criteria, demographic information, and pre‐treatment measures will be collected through a Qualtrics link which will be shared in the study advertisement. Both survivors and their carers will be responsible for self‐screening as their eligibility will be determined based on their responses to the questions set‐up in Qualtrics. The survey is designed to automatically exclude respondents who select “yes” to the questions asking current suicidal ideation or intent, current alcohol or drug misuse, enduring mental health condition (such as schizophrenia, psychosis, and bipolar disorder), and currently being in treatment for depression or anxiety. Participants also required to be at least mildly confident in reading and writing in English and using computers and the internet. Potential participants who responded yes to the questions regarding current suicidal ideation and intent are provided contact details for recommended support services in Qualtrics. Eligible survivors will be able to continue with baseline questionnaires (Time 1) for the assessment of depression and anxiety symptoms, quality of life, coping style, breast cancer‐related worry, perceived social support, relationship, and communication quality with their carer (if they have one). Survivors who have a carer will also be asked whether they would prefer giving their access to the treatment programme content using a separate log in. If they prefer carer access, they are asked to provide their carers’ email address. Eligible breast cancer survivors will be automatically randomized to either iCBT or treatment‐as‐usual control using a 2:1 ratio in Qualtrics. At the end of the baseline assessments, participan CONDITION: Depression and anxiety symptoms in female breast cancer survivors ; Mental and Behavioural Disorders ; Depressive episode, anxiety disorder, unspecified PRIMARY OUTCOME: Depression and anxiety symptoms measured using the Hospital Anxiety and Depression Scale (HADS) at pre‐test, post‐test, and 2‐month follow‐up INCLUSION CRITERIA: Breast cancer survivors and their carers (people who support them such as a partner, family member, or friend) will be recruited online and screened for eligibility using Qualtrics. Survivors: 1. Female 2. Completed breast cancer treatment 3. At least mildly confident with using the internet 4. At least mildly confident in reading and writing in English Main carers: 1. Currently caring or have cared for a woman living with breast cancer (such as partner, spouse, friend, or relative of the patient) 2. At least mildly confident with using the internet 3. At least mildly confident in reading and writing in English SECONDARY OUTCOME: ; 1. Survivors' quality of life measured using a single item from the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ‐C30) at pre‐treatment, post‐treatment, and 2‐month follow‐up; 2. Survivors’ use of coping styles for breast cancer‐related stress measured by Brief COPE at pre‐treatment, post‐treatment, and 2‐month follow‐up; 3. Survivors' cancer‐related worries measured using Cancer Worry Scale at pre‐treatment, post‐treatment, and 2‐month follow‐up; 4. Survivors' perceptions of social support measured using the Emotional/Informational subscale of the Modified Medical Outcomes Study Social Support Survey (MOS‐SS) at pre‐treatment, post‐treatment, and 2‐month follow‐up; 5. Survivors' and carers' communication quality measured using Survivor‐Carer Cancer Communication at pre‐treatment, post‐treatment, and 2‐month follow‐up; 6. Survivors' and carers' relationship quality measured using a single‐item Relationship Quality scale at pre‐treatment, post‐treatment, and 2‐month follow‐up; 7. Helpful aspects of the programme for survivors and carers measured using Helpful Aspects of Therapy Form (HAT) at post‐treatment; 8. Survivors' and carers' satisfaction with the programme measured using Satisfaction with Online Treatment (SAT) at post‐treatment;