Is a medical illness causing your patient’s depression?
Endocrine, neurologic, infectious, or malignant processes could cause mood symptoms
Interferon (IFN) treatment for chronic, active hepatitis C has been associated with increased depressive symptoms and suicidal behavior. In a study of 31 hepatitis C patients, 23% experienced depressive episodes concurrent with IFN alfa treatment.43 Depressive symptoms seem to be related to dose and treatment duration and may take several weeks to develop.
Malignancy
Cancer patients often report depressive symptoms, although a causal relationship between malignancy and depression remains unclear. Some evidence suggests that pancreatic cancer and paraneoplastic syndromes can cause depression. In a retrospective study, depression preceded a pancreatic cancer diagnosis more often than with other gastrointestinal or non-gastrointestinal cancers.44 Typically, depression starts >1 year before the cancer is discovered. It is unclear, however, if the cancer leads to depression or depression predisposes a person to pancreatic cancer.
Signs and symptoms. New-onset depression, dramatic unintended weight loss, and predominant sleep disturbance warrant further evaluation for malignancy. In patients diagnosed with cancer, depressive symptoms may be caused by reactive depression, an acute stress reaction, or adjustment disorder with depressed mood.
Paraneoplastic syndromes can cause depression, behavior and personality changes, and memory deficits.45 These syndromes are commonly found in breast, lung, and testicular cancer, all of which might not be discovered when psychiatric symptoms develop.46
The immune system’s reaction to cancer produces antibodies that attack the nervous system. Diagnosis of the resulting limbic encephalitis thought to underlie psychiatric symptoms is by CSF-positive antibodies (anti-Yo antibodies, anti-Ma2 antibodies, or anti-Hu) and abnormalities in brain MRI. Psychiatric symptoms often improve when the underlying malignancy is treated.
Related resources
- Blumenfield M, Strain JJ. Psychosomatic medicine. Philadelphia, PA: Lippincott, Williams, & Wilkins; 2006.
- Ferrando SJ, Freyberg Z. Neuropsychiatric aspects of infectious diseases. Crit Care Clin. 2008;24:889-919.
Drug brand names
- Bupropion • Wellbutrin, Zyban
- Felbamate • Felbatol
- Interferon alfa • Intron, Roferon
- Interferon beta • Avonex, Rebif
- Isotretinoin • Accutane
- Levetiracetam • Keppra
- Phenytoin • Dilantin
- Primidone • Mysoline
- Propranolol • Inderal
- Tiagabine • Gabitril Roferon
- Topiramate • Topamax
- Verapamil • Isoptin
- Vigabatrin • Sabril
- Varenicline • Chantix
Disclosures
Dr. Carroll reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.
Dr. Rado receives research support from Eli Lilly and Company, Neuronetics, and Otsuka, and is a speaker for Eli Lilly and Company.
