The prevalence and pharmacotherapy of depression in cancer patients

Abstract

Background

Depression is a frequent and serious comorbid condition in cancer patients that may require special attention. We investigate the prevalence of depression in cancer and review the current state of evidence regarding the effectiveness of drug treatment of depression in this group.

Methods

We conducted a literature search for reports of prevalence rate of Major Depressive Disorder (MDD) in cancer patients based on Structured Clinical Interview based on DSM (SCID). We estimated the prevalence rate by combining the data of all reports. In addition we identified controlled trials studying the effect of psychotropic drugs in depressed cancer patients.

Results

Based on the 31 reports, the estimated prevalence rate of depression in cancer patients is 10.8% (996/9248). There were 8 trials comparing antidepressant with other active treatment in cancer patients. Only mianserin and alprazolam demonstrated to improve the depressive symptoms.

Limitations

This literature review cannot resolve the challenge of diagnosing depression in severely ill and is subject to publication bias.

Conclusion

Despite the high prevalence of depression in cancer patients, studies on effective pharmacotherapy are relatively scarce. The evidence for the efficacy of conventional medication used for the treatment of depression such as tricyclics antidepressants and selective serotonin reuptake inhibitors is very limited. It is possible that they may be less suitable in this setting because of their relatively late onset of action. The use of psychostimulants which have a rapid onset of action therefore deserves more attention.

Introduction

Cancer remains one of the most feared illnesses and the diagnosis of cancer has huge psychological impact on the patients and their care-takers (Knobf, 2007). Depression is one the most common psychiatric sequelae (Derogatis et al., 1983) and affects the quality of life, compliance to treatment, disease advancement, tolerability to pain and fatigue in cancer patients (Somerset et al., 2004, Bennett et al., 2004, Green et al., 2009). However, it is likely that depression is under-recognized and under-treated in cancer patients (Kadan-Lottick et al., 2005).

Depressed feelings manifest in a spectrum ranging from normal sadness to a variety of mood disturbances and clinical presentations. It is challenging to differentiate clinical depression from “normal” emotional distress in cancer patients (Massie & Popkin, 1998, Cochinov, 2001, Jesse et al., 2008) and the somatic symptoms such as fatigue, loss of appetite or weight, sleep difficulties, poor memory and concentration may mirror the physiological symptoms caused by cancer or its treatment. This complicates the diagnosis of depression in cancer patients (McDaniel & Musselman, 1995, Massie & Popkin, 1998, Cochinov, 2001, Pasquini & Biondi, 2007, Jesse et al., 2008).

Many studies have investigated the prevalence of depression in cancer in the past decades. A previous review by Mc Daniel et al., reported a prevalence of major depression ranging from 4.8% to 9.2% based on studies using standardized diagnostic interviews on cancer outpatients. Prevalence rates were higher among admitted cancer patients (8% for Major Depression and 15% to 36% for all depressive disorders) (McDaniel and Musselman, 1995).

The reported prevalence of the studies varies significantly due to the methodological inconsistencies. Different diagnostic criteria, measurement tools and scales were used to study depression in different types of cancer (Derogatis et al., 1983, Kathol et al., 1990, Massie & Holland, 1990, Sellick & Crooks, 1999). Several diagnostic alternatives (Trask, 2004) such as inclusive (discounted the cause of the symptoms) (Rifkin et al., 1985), etiologic (symptoms only counted if clearly not attributed to the physical illness) (Spitzer et al., 1990), substitutive (e.g., Edincott criteria) (Endicott, 1984) and exclusive (e.g., Cavanough criteria) (Judd et al., 1991) approaches were suggested. However, to-date, the standard method has not yet been established (Kathol et al., 1990, McDaniel & Musselman, 1995). The most commonly used diagnostic method is the Structured Clinical Interview based on DSM (SCID) (Spitzer et al., 1990).

In addition to the problems in diagnosing depression, the optimal treatment of depression in cancer is not established. Although a huge number of studies investigated the efficacy of pharmacotherapy for depression in general population, the number of randomized, controlled trials of antidepressants on depression in cancer patient is limited (Challman & Lipsky, 2000, Raison & Miller, 2003, Rodin et al., 2007). A comprehensive systematic review looking into the effectiveness and tolerability of antidepressant treatment in depressed cancer patients was performed and published by Rodin et al. (2007). Although 7 trials were identified, the authors commented that the number of randomized trials was limited and concluded that there is a need for more rigorous studies on other newer agents and alternative treatment option. The effectiveness of psychostimulants drugs in the treatment of depression in cancer is not reported.

The aims of this systematic review are to summarize the current evidence regarding the prevalence and treatment of depression in cancer patient. Due to the methodological variation in the various reports, we will focus on the reports using the most established and accepted diagnostic tool, which is the Structured Clinical Interviews based on DSM (SCID). Secondly, we update and extend the work by Rodin et al. by including psychostimulants in identifying pharmacological studies on psychotropic drugs in this group of patients.