Fast Five Quiz: Depression and Cognition

Stephen Soreff, MD


December 31, 2019

MDD has consequences for patients' physical as well as mental health. An ECG may be indicated in the workup of patients presenting with depressive symptoms for the diagnosis of arrhythmia, especially heart block. An EEG may also be indicated in some patients.

Cognition should be assessed in all patients presenting with depression. Cognitive deficits may affect attention, verbal and nonverbal learning, short-term and working memory, visual and auditory processing, problem-solving, processing speed, and motor functioning. To evaluate improvement, cognition should be assessed and documented in the same way at every visit. Additionally, psychometric tests—for example, the Zung Self-Rating Depression Scale, the Beck Depression Inventory, the Criteria for Epidemiologic Studies-Depression scale, and the Yesavage Geriatric Depression Scale—can yield clinically useful information related to depression and cognition. These tests not only help in making the diagnosis of MDD, but they also provide an instrument to monitor the effects of treatment.

Laboratory studies can be valuable adjuncts to rule out potential medical illnesses that may present as depression and cognitive decline. These may include:

  • Complete blood cell count

  • Thyroid-stimulating hormone

  • Vitamin B12

  • Rapid plasma reagin

  • HIV test

  • Electrolytes, including calcium, phosphate, and magnesium levels

  • Blood urea nitrogen and creatinine

  • Liver function tests

  • Blood alcohol level

  • Blood and urine toxicology screen

  • Arterial blood gas

  • Dexamethasone suppression test (Cushing disease, but also positive in depression)

  • Cosyntropin (ACTH) stimulation test (Addison disease)

  • Pulmonary function testing

Neuroimaging modalities such as CT scanning or MRI of the brain can help illuminate the nature of a neurologic illness that may generate psychiatric symptoms, but their value in patients who do not have distinct neurologic deficits may be questionable. CT scanning and MRI should be considered if organic brain syndrome or hypopituitarism is included in the differential diagnosis.

Learn more about the workup of patients with depression.

Learn more about depression-related cognitive dysfunction.


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