A 40-year-old woman comes to the office due to worsening anxiety and insomnia over the past 3 months. She says, "I'm really worried that something is wrong with me. I was never a particularly anxious person, but now I feel anxious all the time. Sometimes I feel panicky for no reason; my heart races and I break out in a sweat. The only benefit is that I have lost 5 pounds (2.3 kg) without even trying." The patient has no significant medical or psychiatric history. She drinks 2-3 glasses of wine per week and does not smoke or use illicit drugs. Blood pressure is 130/90 mm Hg and pulse is 112/min. On physical examination, the patient is restless and has warm, moist skin and mild hand tremor bilaterally. Mental status examination is notable for a frightened stare, anxious mood, and rapid speech. Which of the following is the most likely diagnosis?
Anxiety and insomnia are nonspecific symptoms that can be due to a variety of medical and psychiatric disorders. Diagnosis of primary anxiety disorders requires ruling out medical illness and substance-induced etiologies (due to medications, drugs of abuse, or toxins). Chronic anxiety and insomnia (as seen in generalized anxiety disorder) and panic attacks (as seen in panic disorder) can be symptoms of a medical illness or substance intoxication or withdrawal.
The new onset of anxiety in this patient with no psychiatric history and prominent physical findings on examination suggests that anxiety is more likely due to another medical condition (ie, the anxiety is a direct physiological effect of the medical condition) than to a primary anxiety disorder. Specifically, this patient's weight loss without trying; tachycardia; warm, moist skin; tremor; frightened stare (possible eyelid retraction); and restlessness are consistent with hyperthyroidism. Other medical conditions known to present with anxiety symptoms include hypoglycemia, pheochromocytoma, hypercortisolism, and cardiac arrhythmias. Common substance-induced etiologies include sympathomimetic drugs, caffeine, stimulant intoxication, and alcohol and sedative-hypnotic withdrawal.
(Choice A) Alcohol withdrawal can present with anxiety, insomnia, tremulousness, palpitations, and diaphoresis. However, the extent of this patient's alcohol use would not result in dependence and withdrawal.
(Choices C and E) Primary anxiety disorders should not be diagnosed when anxiety symptoms are caused by a medical condition. Generalized anxiety disorder is characterized by excessive, uncontrollable worry about multiple issues. Symptoms must persist for at least 6 months, whereas this patient's symptoms have lasted only 3 months. Panic disorder involves recurrent, unexpected panic attacks.
(Choices D and F) These disorders involve either having a serious undiagnosed medical illness (illness anxiety disorder) or excessive preoccupation with one or more somatic symptoms (somatic symptom disorder). They would not be diagnosed in this patient, who has legitimate concerns about symptoms that have not yet been evaluated.
Educational objective:
The differential diagnosis of anxiety includes medical conditions and substance-induced etiologies (eg, intoxication, withdrawal). Primary anxiety disorders are not diagnosed when anxiety is caused by the physiological effects of a medical condition (eg, hyperthyroidism) or drug.