Mood disorders in cancer patients

‘If I can’t feel, if I can’t move, if I can’t think, and I can’t care, then what conceivable point is there in living?’ (Kay Redfield Jamison, An Unquiet Mind: A Memoir of Moods and Madness) Mood is a person’s subjective emotional state. According to the DSM-IV the term mood disorder is used for a group of diagnoses where the primary symptom is a disturbance in mood, or in other words the experience of an inappropriate, exaggerated or limited range of feelings. Mood disorders can mainly be divided into two groups: (1) depressive episode(s) characterised by feelings of sadness, hopelessness, helplessness, guilt, suicidal thoughts, fatigue, appetite changes, concentration problems and troubles engaging in daily living tasks; (2) manic or hypomanic episode(s) characterised by feelings of grandiosity, extreme energy and heightened arousal. Several treatment options are available for mood disorders – e.g. medication, cognitive and/or behavioural therapy – depending on the severity and the evaluation of the health-care provider. Several studies have shown that mood disorders are common in patients with cancer. In a meta-analysis, the point prevalence of major depression was about 16% and that of anxiety was 10% [1]. The exact causes of mood disorders are largely unknown, but it is hypothesised that an imbalance in neurotransmitters is likely to play a role. The mood disorder can be triggered by the cancer diagnosis on its own, or it can be treatment-induced in cases where the aetiology can be found in the physiological effect of a psychoactive drug or chemical substance. These articles provide an overview of the most common mood disorders among cancer patients. First, Dr. Dauchy will discuss the prevalence, predictive factors and treatment options of depression, one of the most under-diagnosed and inadequately treated mood disorders among cancer patients. Second, Professor Caraceni will introduce drug-associated delirium, an altered state of consciousness with reduced awareness of self and the environment, which may go hand in hand with the inability to think and talk clearly and rationally, hallucinations, disorientation and cognitive impairment. Third, Dr. Die Trill will discuss anxiety, one of the most frequently reported reactions to a cancer diagnosis, which may persist throughout the cancer continuum. In addition, she will shine her light on sleep disorders, which are frequently associated with psychological disorders. Finally, Dr. Schagen will describe the chemotherapy-related changes in cognitive functioning, which can result in diminished functional independence and can last throughout the survivorship period.