Background   Diagnosing and providing treatment for a major depressive episode in patients with advanced cancer can improve quality of life.  However, diagnosing major depression in an advanced cancer can be complicated by the fact that many cancer symptoms overlap with the somatic symptoms of depression.   Furthermore, although depressive thoughts and symptoms may be present in up to 15-50% of cancer patients, only 5% to 20% will meet diagnostic criteria for major depressive disorder.  This may create a clinical dilemma in determining when it is appropriate to add pharmacotherapies for depressive symptoms or whether reflective listening and exploration of the patient’s concerns may be the only needed intervention. 

Assessment    Clinicians often rely more on the psychological or cognitive symptoms of depression (worthlessness, hopelessness, excessive guilt, and suicidal ideation) than the physical/somatic signs (weight loss, sleep disturbance) when making a diagnosis of major depressive disorder in advanced cancer patients.  Endicott has proposed substituting somatic criteria with affective criteria when evaluating depression in advanced cancer patients:

Physical/somatic symptoms …

1. Change in appetite/weight
2. Sleep disturbance
3. Fatigue, loss of energy
4. Diminished ability to think or concentrate

… are replaced by psychological symptoms

1. Tearfulness, depressed appearance
2. Social withdrawal, decreased talkativeness
3. Brooding, self-pity, pessimism
4. Lack of reactivity, blunting

Screening Tools    The Association of Palliative Medicine Science Committee performed a thorough assessment of available screening tools and rating scales for depression in palliative care.  While they found that commonly used tools such as the Edinburgh Depression Scale and the Hospital Anxiety and Depression Scale have validated cut-off thresholds for palliative care patients, the depression screening tool with the highest sensitivity, specificity and positive predictive value was the single question: “Are you feeling down, depressed, or hopeless most of the time over the last two weeks?”

Other Etiologies    Medication side effects from commonly used therapeutics in this patient population, like chemotherapeutic agents, opioids, benzodiazepines or glucocorticorticoids, can mimic the symptoms and signs of depression.  Clinicians should be especially aware of hypoactive delirium in the differential diagnosis of depressive symptoms in cancer patients. Delirium is a particularly important consideration in the final days of life as its prevalence may reach up to 90% during this critical time.

Teaching Point: The key indicators of depression in the terminally ill are persistent feelings of hopelessness and worthless and/or suicidal ideation.   Symptoms of depression can overlap with those of anticipatory grief, a normal aspect of the dying process. See Fast Fact # 43 for a complete description of anticipatory grief and how to differentiate from major depression. See Fast Fact #146 on screening for depression in palliative care.

References

1. Endicott J. Measurement of depression patients with cancer. Cancer. 1983; 53:2243-8.
2. Block SD. Assessing and managing depression in the terminally ill. Ann Inter Med. 2000; 132:209-217.
3. Chochinov H, et al.  Prevalence of depression in the terminally ill: effects of diagnostic criteria and symptom threshold judgments.  Am J Psychiatry 1994;151:537-40.
4. Massie MJ.  Prevalence of depression in patients with cancer.  JNCI Monographs 2004;57-71.
5. Spiller JA, Keen JC.  Hypoactive delirium: assessing the extent of the problem for inpatient specialist palliative care.  Palliative Med 2006;20:17-23.
6. Williams ML, Spiller J.  Which depression screening tools should be used in palliative care.  Pall Med 2003;17:40-43.
7. Chochinov HM, et al.  “Are you depressed?”  Screening for depression in the terminally ill.  Am J Psychiatry 1997;154:674-6.

Version History:  This Fast Fact was originally edited by David E Weissman MD.  2nd Edition published July 2005; 3rd Edition May 2015. Current version re-copy-edited May 2015.