Depression and cancer: physiological and psychological markers

Abstract

Aim: To investigate potential markers for depression and poor quality of life (QoL) in head and neck (HN) and colorectal (CR) cancer patients. Background: Comorbid depression is strongly related to decreased QoL in cancer patients and may increase the risk of mortality. Many psychosocial factors, such as childhood trauma (CT), neuroticism (NE), past history of depression (PH) and current life events (LE) increase the risk of depression. Depression is also associated with increased levels of pro-inflammatory cytokines and patients with comorbid depression and cancer show higher levels compared to patients with either condition alone. Thus, increased inflammation may also be a risk factor for low mood. This thesis explores relationships between inflammation and psychosocial risk factors and their potential as predictive markers for depression in cancer patients. Methods: Ninety-one newly diagnosed cancer patients due for surgical treatment (57 HN and 34 CR) completed the Hospital Anxiety and Depression Scale and European Organisation for Research and Treatment of Cancer QoL Questionnaire before surgery and one, three and six months following surgery. Patients gave blood samples before and one week and one month after surgery to measure levels of C-reactive protein and pro-inflammatory cytokines and saliva samples before surgery. The Brief Life Events Questionnaire was completed at one month and the Eysenck Personality Questionnaire, Childhood Trauma Questionnaire and Brief COPE at three months. Patients completed a diagnostic interview between three and six months for diagnosis of past or current episode of depression. Results: Childhood trauma, NE, PH and LE were all related to low mood and poorer QoL. Increased inflammation was associated with lower mood post treatment in CR patients, but there were fewer associations in the HN patients. Conclusions: Both psychosocial and inflammatory markers are related to lower mood after treatment. PH is a simple but informative marker for increased risk of depression in cancer patients.