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 5-20% 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.
Endicott has proposed substitution criteria:
1. Change in appetite/weight
2. Sleep disturbance
3. Fatigue, loss of energy
4. Diminished ability to think or concentrate
Psychological symptom substitute
1. Tearfulness, depressed appearance
2. Social withdrawal, decreased talkativeness
3. Brooding, self-pity, pessimism
4. Lack of reactivity
The key indicators of depression in the terminally ill are persistent feelings of hopelessness and worthless and/or suicidal ideation.
Commonly used tools, such as the Edinburgh Depression Scale and the Hospital Anxiety and Depression Scale, have validated cutoff thresholds for palliative care patients. However 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?”
Medication side effects from commonly used therapeutics in this patient population, like chemotherapeutic agents, opioids, benzodiazepines or glucocorticosteroids, 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.
See reference for details.
Adapted from Warm E and Weissman DE. Fast facts and concepts #7. Assessing depression in advanced cancer. Internet. Accessed on January 26, 2016.