BackgroundBreast cancer patients often experience a high level of distress. Psychological distress is a broad construct encompass both depression and anxiety. Previous studies in examining which of these psychological symptoms (either anxiety or depression) were more significantly associated with the distress level in breast cancer patients is lacking. This study aims to compare the level of depression and anxiety between patients with different level of distress. The correlation between the changes in distress level with depression or anxiety over 12 months was also examined.MethodsThis study is from the MyBCC cohort study. Two hundred and twenty one female breast cancer patients were included into the study. They were assessed at the time of diagnosis, 6 months and 12 month using Hospital Anxiety and Depression Scale (HADS) and distress thermometer. The information on age, ethnicity, treatment types and staging of cancer were collected.Results50.2%, 51.6% and 40.3% of patients had perceived high level of distress at baseline, 6 months and 1 year after diagnosis. Those with high perceived level of distress had significant higher anxiety scores even after adjusted for the underlying depressive scores (Adjusted OR at baseline = 1.28, 95% CI = 1.13–1.44; adjusted OR at 6 months = 1.27, 95% CI = 1.11–1.45; adjusted OR at 12 months = 1.51, 95% CI = 1.29–1.76). There were no significant differences in the depressive scores between the subjects with either low or high distress level. There was reduction in perceived level of distress, anxiety and depression scores at 12 months after the diagnosis. The decrease of distress was positively correlated with the reduction of anxiety scores but not the changes of depressive scores (r’ = 0.25).ConclusionAnxiety is a more significant psychological state that contributed to the feeling of distress in breast cancer as compared with depression. Levels of anxiety at diagnosis in this study would justify screening for anxiety, early identification and therapy for maintaining the psychological well-being of breast cancer patients. Further studies will be needed to measure the effectiveness of therapeutic interventions.