Is screening effective in detecting untreated psychiatric disorders among newly diagnosed breast cancer patients

A NIH Consensus Conference Statement1 and an IOM report 2 have identified detection and management of distress and psychiatric disorder among cancer patients as a priority. Screening is often proposed as a first step in providing appropriate psychosocial and mental health care, and as a means of reducing morbidity and improving quality of life 3–5. Evidence-based guidelines for managing distress, however, are still being developed 6. Moreover, a considerable proportion of positive screens for distress represents psychiatric disorder, typically 30 to 45%7–8. Such disorders tend to be chronic, episodic, and recurrent. They require more intensive care and longer follow-up, but have the advantage of an agreed upon nosology and well-defined, empirically-based treatment guidelines. Evaluations of screening instruments, therefore, typically make gold standard comparisons against validated diagnostic interviews for psychiatric disorders9–10. Questions have been raised about the appropriateness of particular screening instruments for specific subgroups of cancer patients 11–12, though most screening instruments appear to have moderate performance compared to diagnoses based on psychiatric interviews10. Even the best performing instrument cannot be used diagnostically, and so screening is best construed as an initial step in a process in which positive screens are followed by a diagnostic interview13. Given the modest prevalence of psychiatric disorder in most cancer populations, however, most positive screens will be found to be false positives, rendering screening potentially inefficient8. Routine screening programs assume that screening provides a means of uncovering distress and psychiatric disorder that would not otherwise be identified and treated14–15. In clinical practice, the interest is not in detecting patients already being treated, but in those who would otherwise be missed. A shortcoming of existing studies of the accuracy and yield of screening tools in cancer care is that they are almost always conducted with all available patients, including patients who have already been recognized and are receiving treatment for psychiatric disorder, inflating estimates of the number of patients in need of treatment that screening can yield. A recent systematic review of the diagnostic accuracy of screening instruments for depression found only 8 of 197 (4.1%) unique publications from 17 systematic reviews and meta-analyses specifically excluded patients already diagnosed or being treated for depression15. Only 2 of the 8 concerned cancer patients11,17, both of which were from the same sample, and these simply excluded diagnosed or currently treated depression without determining the effect of doing so on screening performance. Patients with a psychiatric disorder who are already in treatment may differ from those who are not by having more conspicuous disorder or more positive attitudes about treatment 18. Patients for whom screening represents the only means of identifying psychiatric morbidity may, therefore, be more difficult to diagnose and require additional resources to overcome resistance to treatment, while those already in treatment but remaining sufficiently symptomatic to screen positive may require improved surveillance and greater coordination of care with outside providers. Routine care for depression in the community tends to be inadequate, with low adherence, high rates of unsupervised discontinuation of treatment, and a lack of scheduled follow-up visits19–20. These problems suggest the value of surveillance of existing treatment, with a recognition that the clinical resources required would differ substantially from those required if the goal were simply initiation of new treatment based on screening. We sought to evaluate the performance of screening among newly diagnosed breast cancer patients, comparing screening results to a validated diagnostic interview, first, as is typically done, ignoring whether patients were already in treatment, and, second, taking existing psychotropic treatment into account. We chose newly diagnosed patients as there is evidence that distress is most prominent early in the cancer trajectory 21–26 and predicts long term adaptation27. Our objectives were to (1) evaluate the ability of a screening instrument to detect depression and other psychiatric disorders among a sample of patients in early treatment for breast cancer, and (2) determine how screening performance is affected when existing treatment for disorder is taken into account.