Meaningful research on interventions for distress among cancer patients has long been hamstrung by the dearth of solid science about the true prevalence of anxiety and depression in this population.
Reported prevalence rates for depression in cancer patients range wildly and utterly unhelpfully from 0 to 38% for major depression in one study and from 0 to 46% in another. Trying to pin down the prevalence for anxiety is nerve-rackingly vague as well, with reported rates between 1% and 49%.
How many cancer patients cope well – and how many suffer the toxic toll of anxiety and depression, which have the potential to compromise compliance, undermine quality of life, and drive excess mortality?
A refreshingly comprehensive look at distress prevalence shortly after diagnosis has recently been published by a group of researchers at the University of British Columbia and the BC [British Columbia] Cancer Agency, (J. Affect. Disord. 2012;141:343-51 [doi:10.1016/j.jad.2012.03.025]).
A study of 10,153 consecutive cancer patients found that shortly after diagnosis, approximately 19% met diagnostic criteria for an anxiety disorder and nearly 13% for clinical depression, with an additional 22.6% and 16.5% demonstrating symptoms of anxiety and depression, respectively.
The numbers offer just a snapshot in time, capturing the period in which individuals are coping with the fresh news of a diagnosis, but before the rigors of treatment or recurrence have begun to weigh upon them.
For patients with diagnoses facing brutal but promising treatments (head and neck patients come to mind), this portrait may appear misleadingly rosy. Indeed, compared with the "grand mean," head and neck cancer patients were less depressed at the time of the study than patients with other forms of cancer.
Had the patients been examined weeks or months into treatment, when some could no longer eat or speak normally, the rates of depression might have been far different.
And yet, how valuable to have a foothold into the prevalence conundrum. I highly recommend reading the study itself for insight into differences among patients by age, cancer type, and gender.
But here’s the Cliff Notes version:
Patients with lung, gynecologic, and hematologic cancer had the highest levels of distress at the time of diagnosis.
Women were significantly more distressed than were men across all cancer types, paralleling findings among adults who do not have cancer. As the authors note, "This gender difference may reflect a ... difference in willingness to report distress but could also arise because women tend to use emotional approach coping."
In some forms of cancer, the gender disparity was especially pronounced.
For example, women with hematologic cancers were the most distressed of all patients, with rates of anxiety two standard deviations above the \"grand mean\" and rates of depression far higher than average newly diagnosed patients in the study. Men with hematologic cancers, on the other hand, were far closer to the average in terms of depression, while their anxiety rates were actually lower than grand mean.
Age also mattered.
In a finding that has become increasingly consistent in research populations, younger adults with cancer reported more distress than did older adults. Although little difference was seen among patients with poor-prognosis cancers, in most cases, a diagnosis in patients younger than age 50 years revealed higher rates of both anxiety and depression.
Finally, the authors offered a caveat that their overall findings reflect emotional well-being in Canada’s economically protective vacuum, suggesting that in the United States, where a diagnosis can have catastrophic economical consequences, rates of depression and anxiety may be higher.
In their words, "We also need to sensitize readers to the fact that the data reflect the population of one limited geographical area in which all patients receive a similar quality of universal, third-party paid health care. Cancer may be perceived as an even greater threat when patients worry about medical bills that may exceed their resources, or have reason to fear loss of a job if their country of residence does not provide illness leaves and disability pensions."
Dr. Freed is a psychologist in Santa Barbara, Calif., and a medical journalist.