The hierarchy of evidence for arguing causality of a disease by any factor consists of epidemiological and, ultimately, treatment studies. The application of these criteria to chronic negative emotion as a risk factor for ischemic heart disease (IHD) is relatively new. However, controlled prospective evidence now indicates that anger, depression, and anxiety may play a major role in the genesis of IHD. And the strongest form of evidence, a controlled clinical trial that used randomly assigned subjects, exists, implicating anger as a strong predictor in the development of IHD. Resistance to the utility of this avenue of care is not based on evidence alone because widely accepted risk factors and/or treatment modalities often have less persuasive evidence, or less powerful effects, than do the emotional factors. Rather, such resistance is largely due to "paradigmatic scotomata"--conceptual difficulties for those not familiar with biopsychosocial research. Routine psychometric screening of IHD patients may provide a cost-effective means of alerting cardiologists and internists to the relatively high levels of distress among their patients.