The Effect of Acceptance and Commitment Therapy-Based Psychoeducation on Anxiety, Depressive Symptoms, Psychological Flexibility, Mindfulness and Valuing in Cancer Survivors: A Randomized Controlled Trials

According to World Health Organisation data, approximately one in six deaths is due to cancer (WHO, 2022). With the development of healthcare services, cancer survival rates are increasing and progress is being made in the treatment of the disease, but the physical and psychosocial effects of cancer on individuals continue (Li, Guo, Li & Yang, 2021). In recent years, new approaches have been developed to support the mental well-being of cancer patients. The foremost of these is Acceptance and Commitment Therapy (ACT). ACT is an approach developed as a result of the interaction between empirical data obtained from scientific research on human behaviour and clinical experience. ACT, which comes from a humanistic model, emphasises awareness and self-compassion. As a behavioural therapy, ACT draws its origins from the perspectives of Skinner and Pavlov and is based on the Relational Frame Theory, which focuses on the nature of human language and cognitive processes. ACT aims to increase functionality and enable individuals to live more meaningful and valuable lives by using mindfulness. ACT intervention consists of six important cognitive processes. These are a therapeutic approach model consisting of values, contact with the present moment, cognitive defusion, acceptance, contextual self, and committed action. The aim of this study is to examine the effect of acceptance and commitment therapy-based psychoeducation applied to cancer survivors on individuals' anxiety, depressive symptoms, psychological flexibility, acceptance, value-oriented life, and awareness.

The study consists of survivors diagnosed with one of the following types of cancer: breast, gynaecological, colon, or rectal. Participants will be invited to join the study via telephone from the oncology unit's database, targeting patients who have completed these treatments within the past 1-12 months. Accepting patients will first be interviewed in person, and the HAD scale will be administered. Participants who meet the eligibility criteria will be included in the study. Inclusion criteria: - Being between 18 and 65 years of age, having completed cancer treatment, being able to speak Turkish, and, according to the Hospital Anxiety and Depression (HAD) scale, having distress in one or both of the depression or anxiety subscales (HAD-A ≥ 10 and/or HAD-D ≥ 7 based on the cut-off score), and having internet access. The exclusion criteria for the study are receiving another psychosocial intervention, cancer metastasis or recurrence, use of psychiatric medication other than antidepressants, and initiation of antidepressant treatment in the last three months.

The aim of this study is to examine the effect of acceptance and commitment therapy-based psychoeducation applied to cancer survivors on individuals' anxiety, depressive symptoms, psychological flexibility, acceptance, value-oriented life, and awareness.

For the sample calculation required for the study, the G power statistical analysis programme was used, with a Type I error of 0.05, a Type II error of 0.20 (power 0.80), and an effect size of 0.25, and an ANOVA test was applied. Anticipating possible losses in the sample, a total of 32 participants, 16 in each group, are planned to be included. In the data analysis of the study, descriptive statistics will be expressed as numbers (n) and percentages (%) for discrete variables and as mean ± standard deviation (minimum-maximum) for continuous variables. In all analyses, p-values less than 0.05 will be considered statistically significant. The normality of continuous variables will be determined based on Shapiro-Wilks test values, normality tests, and histograms. The similarity of the experimental and control groups will be evaluated using the chi-square test for categorical variables and the t-test for continuous variables. The comparison of the levels of the outcome variables of the experimental and control groups before the intervention will be performed using the t-test. For the evaluation of repeated measurements (depressive symptoms, psychological flexibility, mindfulness, and value), a two-way analysis of variance will be used. For the evaluation of missing data, the Intention to Treat principle will be applied.

The study is planned to be conducted in a randomised controlled experimental design in accordance with CONSORT. The study is planned to be conducted between September 2025 and December 2026 at X Hospital with individuals who have completed cancer treatment. Individuals who are at risk for depression or anxiety in one or both of these sub-dimensions according to the Hospital Anxiety and Depression (HAD) scale will participate in the study. Individuals will be contacted by telephone and will first undergo a face-to-face interview. The psychoeducation sessions will be conducted online, individually, in approximately 30-minute sessions over 6 sessions. A total of 32 individuals will be included in the study, with 16 in the experimental group and 16 in the control group. Follow-ups will be conducted before the intervention, after the intervention, at 3 months, 6 months, and 12 months. No intervention will be performed on the control group during the application period, and they will be placed on a waiting list. If the intervention is found to be effective after the study is completed, it is planned to apply the programme to the volunteer participants in the control group.