Anti-Depressant Use in Patients with Multiple Myeloma Less Common Than Expected

Background: Depression is more common in patients with multiple myeloma (30%) than in the general population (7%), similar to other patients with advanced cancer (PMID 27141015, 20187072). It may be more difficult to detect depression in cancer patients as psychiatric symptoms commonly overlap with medical symptoms from their disease or treatment. Additionally, it is difficult to discern differences between normal and pathologic reactions to such a serious diagnosis. Depressive symptoms, even mild presentations, have been shown to lower quality of life, affect medication compliance, and increase suicide risk, which increase all-cause mortality in the general population, and this is no different in cancer patients, including those with multiple myeloma (PMID 26029972, 23677523). Although depression has a significant impact on cancer patients, there have not been large studies to evaluate antidepressant use, including the frequency of its initiation after diagnosis.

Methods: Patients included in this study were participants in the Ohio Myeloma Initiative (NCT01408225), an observational registry collected from patients in Ohio State University's myeloma clinic. Medications were collected and patients who took antidepressants were filtered into a list. The order date of the medications was compared to the patient's diagnosis date. Patients with order dates occurring after date of diagnosis were collected. Chart review was then performed to determine when the antidepressant was started and its indication.

Results: Fourteen hundred eight-nine multiple myeloma patients were enrolled in the registry and their medications (35,390) compiled. Of those 1,489 patients, 207 (14%) had an antidepressant on their medication list. The most commonly prescribed antidepressants were duloxetine (14%), sertraline (13%), and citalopram (9%). There were 133 male patients and 74 female patients and the average age of diagnosis was 60.2 years. Although 148 patients (148/207, 71.4%) had documentation of antidepressant use after diagnosis. Of these patients, 106 patients (106/148) had the indication of depression with or without anxiety. Other common indications included neuropathy (24/148, 16.2%) and insomnia (13/148, 8.8%). Fibromyalgia, smoking cessation, anorgasmia, and dizziness were rare but documented indications. Only 32 patients (32/207, 22%) were initiated on an antidepressant with the indication of depression after their diagnosis. There were 25 male patients and 7 female patients. Sertraline (22%), citalopram (22%), and escitalopram (18.6%) were the most common antidepressants started for depression.

Conclusions: Only 14% of our patients were on antidepressants despite an average 30% incidence of depressive symptoms reported in prior studies. Of those on antidepressant medications, it would appear that younger patients tended to initiate treatment for their depression, which is congruent with a study by Lamers et al. 2013, which found that younger patients showed the greatest interest in treating their depression. Multiple myeloma is a unique malignancy in that its treatments have side effects, most notably polyneuropathy, which benefit from administration of a SSRI or TCA. Therefore, physicians treating these patients may unconsciously prescribe these antidepressants for a "two birds with one stone" approach. Because documentation of anti-depressant use is often lacking, prospective registries will need to separately document the indications for psychotropic medications.