to the editor: Dr. Kiraly and colleagues introduced an important public health issue in their article on mental illness. They asserted that comorbidity between severe mental illnesses and medical illnesses can result in inadequate treatment of both conditions, with associated increases in morbidity and mortality. I believe that argument can be extended well beyond “serious mental illness” into areas such as “psychotic and bipolar disorders.” In particular, chronic forms of non-psychotic depression and anxiety are associated with increased medical morbidity and mortality.

Results from the National Comorbidity Survey Replication demonstrated that major depressive disorder is common (16.2 percent lifetime prevalence; 6.6 percent prevalence in the past 12 months).¹ Among patients who experienced an episode during the past 12 months, 50.9 percent of the episodes were “severe” or “very severe.” Only 41.9 percent of adults who were depressed received “adequate treatment.”¹ Major depressive disorder is comorbid with several medical conditions (e.g., coronary artery disease, cerebrovascular accident, diabetes mellitus, dementia, Parkinson disease). Research suggests that treatment of comorbid major depressive disorder in the context of medical illness leads to improvement in both conditions.²

Chronic anxiety, in the form of post-traumatic stress disorder (PTSD), is also linked to increased morbidity and mortality. Multiple studies estimate that lifetime incidence of PTSD in patients presenting to primary care ranges from 6 to 36 percent. PTSD is often missed or poorly managed in primary care despite being associated with phenomena familiar to primary care physicians: medically unexplained physical symptoms, poor health-related behaviors (e.g., smoking, alcohol abuse, less exercise, poor diet, obesity, medical noncompliance), increased chronic medical illnesses (e.g., diabetes mellitus, chronic obstructive pulmonary disease), and mental health comorbidity.³ Primary care strategies for the identification and management of patients with PTSD are just beginning to appear.⁴

Various “collaborative care” models manage depression or anxiety according to evidence-based algorithms with defined roles for primary care physicians, mid-level providers, and mental health experts working together. It is well-established that collaborative care is an effective approach for managing major depressive disorder in patients presenting to primary care.⁵ Research studies have begun to investigate the usefulness of collaborative care in the management of various anxiety disorders, including PTSD.⁴

Family physicians have a unique opportunity to address comorbid mental and medical illnesses. To best address our patients' mental and medical health needs and to improve overall health outcomes, we must remain abreast of research on optimal management of common mental health problems, such as depression and anxiety.

editor's note: This letter was sent to the authors of “Primary Care Issues in Patients with Mental Illness,” who declined to reply.