Co-Morbidity Between Cardiovascular Disease And Psychiatric Disorders: What Is The Evidence?

Morbidity and mortality of cardiovascular disease is exceedingly high worldwide. Psychiatric disorders, most notably stress-related disorders such as depressive illness, afflict a significant portion of the population worldwide. Epidemiological studies have confirmed the high co-morbidity between these two entities and the co-morbidity is bidirectional. Systems that are involved in and accountable for this co-morbidity in a major, complex and interactive way include the central and autonomic nervous systems, the neuroendocrine system, the immune system, and the vascular and hematologic systems. Specific pathophysiologic factors across these systems include homeostatic imbalance between the branches of the autonomic nervous system with loss of heart rate variability, sympathoadrenal activation, hypothalamic-pituitary-adrenal axis activation resulting in hypercortisolemia, immune system dysregulation with release of pro-inflammatory cytokines and chemokines, platelet activation and hypercoagulability. Inflammation occurs in cardiac and cardiovascular pathology independent of the presence or absence of depression. A chronic pro-inflammatory status has been documented in numerous studies of depression. Inflammation is closely associated with endothelial dysfunction which is a preamble to atherosclerosis and atherothrombosis. Thus, understanding vascular biology in conjunction with psychiatric co-morbidity is of critical importance. To further unravel the complex intricacies of psychiatric and cardiovascular co-morbidity, a new concept is being proposed. The formation, initially informally, of a subspecialty designated as Psychocardiology, would facilitate and strengthen the relationship between psychiatry and cardiology to the ultimate benefit of patients. Early diagnosis and prevention and appropriately targeted somatic and psychological interventions will significantly reduce morbidity and mortality,