Abstract
INTRODUCTION: Breast cancer stays as one of the most prevalent cancers worldwide, and the increasing number of cases alerts the urgent need for comprehensive support for affected patients. Breast cancer surgery, such as mastectomy, often induces significant psychological distress, including depression, that is particularly pronounced in newly diagnosed patients. The study aims to evaluate the presence of depressive symptoms in newly diagnosed breast cancer patients undergoing mastectomy and assess the effectiveness of group cognitive behaviour therapy (G-CBT) in reducing depression. METHODS: An experimental study was conducted at a large tertiary public hospital in Kuala Lumpur. Seventy (70) newly diagnosed breast cancer patients were recruited and randomly allocated to an intervention (G-CBT) or control group. The PHQ-9 questionnaire was used to assess the level of depressive symptoms at baseline, immediate post-operation, and post operation in the first and third-month follow-up. A mixed design ANOVA analysis was used to determine the effect of G-CBT on depressive symptoms with partial eta squared as a measure of the intervention effect size. RESULTS: The study found that both groups showed significant depressive symptoms above the threshold for clinical attention prior to mastectomy. The evaluation of the effect of G-CBT across time points revealed a general reduction in depressive symptoms for both groups. However, subjects in the G-CBT intervention group showed a significantly greater reduction in depressive symptoms compared to the control group. The effect of G-CBT on depressive symptom scores sustained until the third month after mastectomy and proved that the psychological intervention is effective in alleviating psychological distress. CONCLUSION: G-CBT significantly reduced depressive symptoms in newly diagnosed breast cancer patients and the effect of intervention sustains until third month follow-up. These findings emphasize the value of incorporating G-CBT into standard care practices to provide targeted psychological support and improve mental health outcomes in this vulnerable population.