Treatment of Mood Disorders: Neoplasm
The rates of depression among patients with cancer range from 1.5% to 50%, depending on the location of the primary tumor. The highest prevalence of depression (50%) has been found in patients with pancreatic cancer. A high incidence of depression has been found in patients with neoplasms in other common locations, including the oropharynx, breast, and colon. The usefulness of pharmacotherapy in treating depression has been proven in several clinical studies, with success rates estimated between 73% and 100%. Theoretically, with a decrease in neurovegetative symptoms, the changes in appetite, sleep disturbance, and fatigue could lead to an increased quality of life and potentially alter morbidity and mortality.
TCAs have long been the standard of care of depression in this population as a result of the positive effects of sedation, chronic pain control, and weight gain. However, the usefulness of TCAs is limited by their potential lethal toxicity in overdose, cardiac conduction abnormalities, and potent anticholinergic side effects. SSRIs have several advantages and disadvantages in the oncological patient. The side-effect profile is much more advantageous than that of the TCAs or the MAOIs. Of some concern is the possible gastrointestinal distress found with SSRIs, which could worsen anorexia in patients with cancer and, at least with mirtazapine, the potential for agranulocytosis.
Drug-drug interactions are of great concern especially with antineoplastic agents. Many standard agents such as cyclophosphamide, doxorubicin, and etoposide are metabolized by the CYP3A4 system and could alter drug-protein binding and chemotherapy toxicity. Newer agents such as venlafaxine, based on its low protein binding, might be the preferred choice for patients with active chemotherapy. Atypicals such as bupropion are often used for the oncology patient, but again little data are available for efficacy in these patients. The use of bupropion should be of some concern in patients with neurological tumors or distant metastasis involving the central nervous system because of the decreased seizure threshold associated with this medication.
Psychosocial treatment can be quite effective, as shown by Spiegel et al. (1989) and Fawzy et al. (1995). These classic studies have shown that various psychological and behavioral interventions can improve mood, decrease psychological stress, and improve mortality with several different forms of cancer. An excellent review has been published by Fawzy and colleagues (1995), and readers are referred to it for a more elaborate discussion.
Revision date: July 9, 2011
Last revised: by Dave R. Roger, M.D.