A 39-Year-Old Man With Diarrhea, Weight Loss, and Mood Shifts

Heidi Moawad, MD


May 22, 2023


The patient in this case exhibits signs of hypomania, most likely due to bipolar disorder, which is characterized by periods of depression that alternate with periods of excessive elation or irritability. He describes a current episode of increased energy and optimism, grandiosity, behavioral changes, and diminished sleep. He likes the way he feels and questions what is wrong with it. The discomfort caused by his recent dietary modifications does not discourage him from following the regimen.

His history, which is provided by both the patient and his sister, suggests fluctuations in behavior and mood, possibly dating back 15 years and becoming more defined over the past 3 years. Although the patient has managed to remain productive, it appears that his behavior at times can be irrational. According to his medical records, he has had at least one previously diagnosed depressive episode and might have had similar episodes of high energy and grandiosity in the past.

The patient's gastrointestinal symptoms are recent and appear to be associated with his new diet rather than a chronic gastrointestinal condition such as irritable bowel syndrome or inflammatory bowel disease. The subacute course, intermittent waxing and waning of symptoms, and lack of fever or abnormal blood test results do not suggest a gastrointestinal infection.

The differential diagnosis of conditions that can cause intermittent mood fluctuations and weight changes is broad. The patient's medical history, pattern of symptoms, associated symptoms, and physical examination findings can help narrow the diagnosis to determine whether diagnostic testing could be helpful. No diagnostic imaging or blood tests can confirm a diagnosis of bipolar disorder. It is a clinical diagnosis that can take years to establish. When patients change their care from one physician to another over the years, medical records might not always note symptoms of depression or mania, especially if no treatment (medication or psychotherapy) was established.

In some situations, blood tests may be needed to rule out a medical condition that could present with mood and weight changes, such as thyroid or adrenal disorders. In this case, the patient's weight loss 3 years earlier was intentional. However, sometimes patients with medical conditions might not know definitively whether their weight loss is intentional or unintentional, especially if they have been trying for some time to achieve a goal of weight loss.

Brain imaging studies may identify structural anomalies that could lead to personality changes, such as a brain tumor or a stroke. Given that the patient's behavioral symptoms have occurred over many years, they do not appear to be caused by an acute neurologic condition.


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