Differential Diagnosis

• Single most likely diagnosis
  • Major depressive disorder: The patient's symptoms of difficulty sleeping, decreased appetite, weight loss, tearfulness, and loss of interest in activities (e.g., needlework) are all consistent with major depressive disorder. The duration of these symptoms (3 months) also meets the criteria for this diagnosis.
• Other Likely diagnoses
  • Adjustment disorder with depressed mood: The patient has experienced significant life changes, including increased mobility limitations due to arthritis and social isolation, which could contribute to an adjustment disorder. However, the severity of her symptoms (e.g., significant weight loss, persistent tearfulness) suggests a more severe condition like major depressive disorder.
  • Depressive disorder due to another medical condition: The patient's chronic medical conditions (hypertension, hypercholesterolemia, arthritis) and medications (e.g., naproxen) could potentially contribute to her depressive symptoms. However, there is no clear indication that these conditions are directly causing her depression.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Dementia, Alzheimer type: Although the patient's mental status examination shows some mild cognitive impairment (e.g., distractibility, difficulty recalling objects), her symptoms are not typical of dementia. However, it is essential to consider dementia in the differential diagnosis, especially in an elderly patient, as it can have significant implications for treatment and management.
  • Sleep disorder or other medical condition causing depression-like symptoms: The patient's difficulty sleeping and other symptoms could be related to an underlying sleep disorder (e.g., insomnia, sleep apnea) or other medical condition (e.g., hypothyroidism, anemia). These conditions should be ruled out through further evaluation and testing.
• Rare diagnoses
  • Normal aging: While some degree of sleep disturbance and decreased interest in activities can be expected in normal aging, the patient's symptoms are more severe and persistent than what is typically seen in normal aging.
  • Other rare medical conditions: Certain rare medical conditions, such as pancreatic cancer or other malignancies, can cause depression-like symptoms. Although the patient's concern about cancer is noted, there is no clear indication of an underlying malignancy at this time.