Depression and cancer

ALSO KNOWN AS: Major depression, major depressive disorder, reactive depression, adjustment disorder with depressed features, depression with psychotic features, first episode depression, chronic depression, depression in remission

RELATED CONDITIONS: Anxiety disorder, mood disorder, substance abuse, seasonal affective disorder, borderline personality disorder, schizoaffective disorder

DEFINITION: Depression is conceptualized along a continuum ranging from transient, nonclinical periods of low mood and sadness that remit quickly on their own to a serious, life-threatening clinical disorder requiring aggressive psychiatric intervention. Depression can lead to significant impairment of an individual’s ability to function and is a leading cause of disability worldwide. Depression differs from expected or occasional sadness.

Clinical depression often occurs with cancer because of its chronic and life-threatening nature, but it is not considered typical or expected, which is counter to a common yet erroneous belief that depression and cancer “understandably” go hand in hand. Depression, nonetheless, is one of the most common psychiatric complications in cancer patients.

Risk factors: Depression is most common among cancer patients with advanced disease and with symptoms and discomfort that are not treated or inadequately treated. It commonly coexists with anxiety and is common in individuals with substance abuse problems and other chronic physical and mental disorders. Most cancer patients manifest transient symptoms of depression that are responsive to support, reassurance, and information about what to expect regarding the course, treatment, and prognosis of their disease. Others experience unremitting or recurrent depression requiring aggressive monitoring and intervention. The following list depicts risk factors that favor the development of clinically significant depression within the context of a cancer diagnosis:

• Family history of depression
• Past history of depression, depression treatment, psychiatric hospitalization, or significant psychiatric/personality disorder
• History of unusual, eccentric behavior
• Confusion (may be indicative of an organically based depression)
• Maladaptive coping style
• Dysfunctional family coping or complex family issues
• Limited social support
• Financial problems, including lack of insurance
• Multiple roles, obligations, and stressors; presence of dependent children
• Advanced cancer or cancer in the central nervous system
• Treatment resulting in disfigurement or loss of function
• Inadequate symptoms management
• Treatment that has a depressionogenic effect (certain chemotherapies, steroids, narcotics)
• Poor sleep
• Deficiencies of vitamin B12, folate, iron, calcium, sodium, or potassium
• Imbalance of adrenal or thyroid hormone
• Persistent pain or negative treatment side effects

Etiology and the disease process: Simplistically stated, the etiology of clinical depression, cancer-related or not, is based on a complex interaction of factors. These include genetic predisposition to aberrant neurochemical states that precede or result from an inadequate stress response combined with a distorted, negatively biased cognitive style or worldview that is learned and reinforced early in life. This multidimensional framework indicates the need for a combined psychopharmacologic and psychotherapeutic treatment approach that is well supported in the medical literature. Clinical depression can present as a single episode, be chronic and unremitting, or occur over time with periods of remissions and exacerbations.

A crisis framework helps describe the occurrence of depression in the context of cancer. The acute crisis response (ACR) typically occurs at transitions in the disease trajectory (diagnosis, treatment initiation, recurrence, treatment failure, disease progression). The ACR is characterized by symptoms of anxiety and depression that usually resolve within a short period. Time frames are variable, but the ACR usually resolves when individuals know what to expect regarding treatment, receive reassurance that discomfort can be controlled, and mobilize usual coping strategies and support systems. When symptoms worsen rather than resolve over time or if coping mechanisms are insufficient, depression treatment must be considered regardless of whether diagnostic criteria for a clinical diagnosis are met.

Incidence: Prevalence rates vary depending on the population studied, the cancer site and stage, and the depression evaluation method. Prevalence rates among cancer patients range from 5 percent (lower than general population rates) to 90 percent. In general, studies that use established diagnostic criteria report rates of depression of about 25 percent. Rates of depression are highest among patients with advanced cancer and in studies in which stringent diagnostic guidelines are not used.

Symptoms: Symptoms of depression in cancer populations include the following:

• Persistent sad mood
• Loss of interest or pleasure in typically pleasurable activities
• Feelings of guilt, worthlessness, helplessness
• Crying, not easily comforted
• Frequent thoughts of death or suicide
• Trouble concentrating, indecisiveness
• Appetite change
• Diminished energy that may be mixed with restlessness and anxiety
• Fatigue, loss of energy
• Insomnia or hypersomnia
• Cancer patients also commonly experience feelings of disbelief, grief, and worry about the future.

It is important to consider the difference in the presentation of depression in adults and children. Though many symptoms overlap, children's symptoms may be confused with regular changes in mood due to developmental stages or hormonal shifts.

Diagnosis of cancer-related depression relies heavily on the presence of affective symptoms (the first five symptoms in the list). Neurovegetative symptoms (the last five symptoms in the list) that characterize depression in physically healthy individuals are not good predictors of depression in cancer patients because cancer and its treatment produce similar symptoms. Additional behaviors suggestive of depression include refusal, indecisiveness, or noncompliance with treatment; persistent anxiety and sadness, unresponsive to usual support; unremitting fear associated with procedures; excessive crying, hopelessness that does not diminish over time; an abrupt change in mood or behavior; eccentric behavior or confusion; and excessive guilt or self-blame for illness.

Screening and diagnosis: A formal diagnosis of depression is based on the fulfillment of criteria outlined in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM). The diagnostic subtypes of depression include major depressive disorder (severe depression that lasts for more than two weeks and is particularly amenable to pharmacologic treatment), adjustment disorder with depressed features (depression that occurs in response to a clearly defined event or stressor), dysthymia (chronic, low-level depression that pervades an individual’s personality and daily life), and bipolar disorder (a genetically determined severe form of depression that may or may not alternate between depressive lows and manic highs and is responsive to mood-stabilizing, pharmacologic agents). Major depression and adjustment disorder are common diagnoses among individuals with cancer. Dysthymia and bipolar disorder usually precede a cancer diagnosis or occur for the first time following a cancer diagnosis in those genetically predisposed.

Depressive symptoms not severe enough or of sufficient duration to achieve diagnostic status are the most common type of depressive phenomena in individuals with cancer. Because a formal diagnosis is absent, these symptoms are often ignored despite a common, negative impact. More research on the simultaneous occurrence of cancer and depression is needed, including symptom profiles, clinical treatment trials, and related outcomes.

Several tests screen for depression, but they have not been consistently incorporated into clinical care. Nonpsychiatric providers fail to diagnose and treat depression in as many as 50 percent of cancer patients with depressive disorders. Obstacles to recognizing depression include inadequate provider knowledge of diagnostic criteria, competing treatment priorities in oncology settings, time limitations in busy offices, concern about the stigma associated with a psychiatric diagnosis, limited reimbursement, and uncertainty about the value of screening mechanisms for case identification. In general, if symptoms do not remit in a reasonable time frame, a psychiatric specialist should evaluate the depressive symptoms.

Treatment and therapy: Psychosocial interventions can exert an important effect on patients and their families' overall adjustment to cancer and its treatment. Factors contributing to the diagnosis of depression should influence the treatment approach. Treatments include psychopharmacologic treatment, individual psychotherapy, group therapy, family therapy, marital therapy, or some combination of these.

Antidepressant medication should be chosen based on diagnostic subtype, treatment response, and side effect profile. Bipolar disorder is usually treated with a mood stabilizer, requiring careful monitoring and adjustment, especially during active treatment, as therapeutic blood levels are narrow and can shift dramatically in response to electrolyte and metabolic changes. Major depression treatment commonly includes one of several classes of antidepressants—selective serotonin reuptake inhibitors (SSRIs), selective serotonin and norepinephrine reuptake inhibitors (SSNRIs), tricyclic antidepressants (including amitriptyline, doxepin, and imipramine), and norepinephrine-dopamine reuptake inhibitors (NDRIs). Dosages are typically lower than required in healthy individuals and can positively affect other symptoms the patient might be experiencing, like pain and anxiety. In the oncology setting, a multimodal treatment approach is most effective in treating depression and can have a positive impact on a range of psychosocial and medical outcomes.

Prognosis, prevention, and outcomes: Left untreated, depression can produce a range of negative outcomes, from diminished quality of life to noncompliance with treatment to diminished survival. Depression can be prevented in some individuals by providing preemptive counseling, education, support, and information about resources. Early recognition and treatment offer the best hope for rapid remission. Modern therapies are effective in treating depression, even among cancer patients who are in progressive and terminal stages of illness. Treatment can vastly improve quality of life and diminish suffering. Thus, routine screening and treatment should be a universal aspect of comprehensive cancer care.

Bibliography

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