Medication- or drug-induced anxiety
Medication side effects are another common cause of anxiety symptoms in medical patients. The Table presents an overview of medications and other compounds that are more likely to induce anxiety. Some patients anticipate the negative effects of a new medication to such an extent that they experience a phenomenon referred to as the nocebo response.
Agents that may induce anxiety
Clonidine(Drug information on clonidine)
Methylphenidate(Drug information on methylphenidate)
Levodopa(Drug information on levodopa)
Anxiety as an impersonator of medical illness
In primary care medicine, anxiety often presents in a disguised manner with somatic symptoms that appear to represent a medical illness and are interpreted as such by the patient. This presentation can arise for a variety of reasons, including social and cultural influences as well as psychological needs. Because there is persistent stigma associated with mental illness, it can often be more socially acceptable for physical rather than psychiatric symptoms to develop. Common somatic manifestations of anxiety, often associated with increased autonomic tone, include tachycardia, palpitations, sweating, flushing, dry mouth, dizziness, and tremor. Muscle tension, headaches, and fatigue, although less specific, are also common manifestations.
Many studies have demonstrated the high prevalence of anxiety disorders in primary care practice. 5 Patients with anxiety disorders are particularly high users of medical care, not only in physicians' offices but also in emergency departments. Anxiety is especially prominent in patients who present with somatic patterns in poorly defined syndromes. Not surprisingly, patients with somatoform disorders, including hypochondriasis, somatization disorder, and somatoform pain disorder, have high levels of anxiety that drive the presentation of somatic symptoms. Personality variables such as somatic amplification and sensitivity to anxiety are likely part of the somatization process.
Anxiety and the course of medical illness
Anxiety can also worsen the course of a medical disease, increase health care use, impair function, lead to avoidance, and increase suffering. At one end of the spectrum, anxiety, like pain, is an adaptive response to threat. In many serious medical situations, anxiety prepares a person to identify and then deal more effectively with the real threat. However, when anxiety is excessive and causes dysfunctional behavior, it may complicate or accelerate the normal course of an illness. In the Medical Outcomes Study, primary care patients were monitored for 2 years. 6 Those with comorbid anxiety and a medical condition had significantly poorer physical and emotional function. Data from the National Medical Expenditure Study showed that the presence of an anxiety disorder independently contributed 3.8 extra bed days in medically ill patients. 7
There are obvious clinical examples of patients with anxiety disorders who have difficulty in pursuing appropriate medical care. Patients with phobias relating to the medical world, such as fear of blood, needles, or doctors and dentists in general, avoid ordinary health maintenance. When circumstances finally force them into treatment, these patients often have medical conditions that may be far advanced and less remediable. It may be especially difficult for patients who need to inject themselves, such as those with diabetes mellitus. Persons with social phobias and discomfort may be reluctant to pursue needed care in the public setting of a hospital.