A 40-year-old woman comes to the physician because of poor concentration, feelings of guilt, and suicidal thoughts. She cannot recall when her symptoms specifically began. Her mother and brother have similar symptoms. She has intermittent abdominal pain. She does not drink alcohol because it can trigger her abdominal pain. Physical examination shows no abnormalities. Neurologic examination shows positive Romberg sign. Which of the following is the most likely explanation for this patient’s findings?
Lyme disease
Multiple sclerosis
Porphyria
Somatic symptom disorder
Systemic lupus erythematosus
