Introduction: The Connection Between Medical Illness and Psychiatric Disorders

May 29, 2015

This Special Report focuses on the psychiatric and medical interface of some common medical problems.

[[{"type":"media","view_mode":"media_crop","fid":"37870","attributes":{"alt":"psychiatric comorbidity","class":"media-image media-image-right","id":"media_crop_9939636735384","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"3753","media_crop_rotate":"0","media_crop_scale_h":"93","media_crop_scale_w":"175","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"width: 180px; height: 96px; float: right;","title":" ","typeof":"foaf:Image"}}]]It is with pleasure that I introduce this Special Report on psychiatric and medical comorbidities. In many ways, the important connection between medical illnesses and psychiatric disorders has become increasingly evident, not only among psychiatrists but also among patients, non-psychiatric physicians, payers, and health systems. Patients with psychiatric disorders, particularly schizophrenia, anorexia nervosa, and substance use disorders, have reduced life expectancies compared with the general population. And there is an increased prevalence of medical conditions such as diabetes, hepatitis C, and psoriasis among patients with psychiatric disorders such as depression and anxiety.

Medical treatments for hepatitis C, HIV infection, and Parkinson disease come with risks of psychiatric adverse effects. Furthermore, comorbid psychiatric and medical conditions generate greater health care costs in terms of more frequent emergency department visits, longer duration of hospitalizations, and more complex office visits.

To address these problems, new models of care are being developed to integrate medical and psychiatric care. These models stretch the psychiatrist’s ability to help care for a larger population, with the goal of improving overall medical and psychiatric outcomes. It is clear that our need for understanding medical and psychiatric comorbidities is ever increasing.

This Special Report focuses on the psychiatric and medical interface of some common medical problems. Hepatitis C is an excellent example of a medical condition with many psychiatric correlates. It affects approximately 4 million people in the US and up to 150 million worldwide. The most common route of transmission of hepatitis C is the sharing of intravenous needles among those who abuse substances.

Among patients with substance abuse, there is a high rate of psychiatric illness, especially depression. There is new evidence that the hepatitis C virus is toxic to the brain; furthermore, the standard treatment for most patients with hepatitis C, interferon-α, can induce depression. But the treatment of Hepatitis C is changing rapidly. New antiviral therapies have emerged and are reducing the treatment duration and adverse-effect burden and are improving outcomes for many patients. It is important that the practicing psychiatrist understands the relationship between psychiatric illness and hepatitis C so that he or she can provide effective psychiatric evaluation and management.

Diabetes is another condition discussed in this Special Report. With the expanding waistlines of Americans, the prevalence of diabetes continues to increase: currently 10% of the population is affected. Depression is a common comorbidity of diabetes and complicates its care. Case examples demonstrate the potential benefits of effective collaborative care in the management of diabetes.

Psoriasis is also often associated with psychiatric comorbidity. It is associated with dysfunction of the immune system and dysregulation of the hypothalamic-pituitary-adrenal axis. These irregularities result in abnormal levels of circulating hormones that can affect mood and anxiety states. Psoriasis, which is more common among patients with anxiety disorders, is exacerbated by stress; thus, reducing stress can reduce psoriatic plaques.

I hope you enjoy reading this Special Report and pick up some pearls that will assist you in caring for your patients. The articles presented here would be useful for non-psychiatric physicians as well, and I encourage you to share them with your non-psychiatric colleagues.


Dr Gleason is Professor and Chair of the department of psychiatry at the University of Oklahoma School of Community Medicine in Tulsa. She reports no conflicts of interest concerning the subject matter of this Special Report.