Recognizing medical symptoms that can mimic psychiatric diagnoses with Dr. Richa Bhatia

Richa Bhatia, MD, conducts a Masterclass on how to identify medical and neurologic illnesses that present with psychiatric symptoms and mimic psychiatric diagnoses.

Dr. Bhatia is a board-certified general and child and adolescent psychiatrist in private practice. She has no disclosures.

Take-home points

Psychiatric diagnoses are diagnoses of exclusion. Psychiatric clinicians must maintain a high level of clinical suspicion for medical and neurologic illnesses that present with psychiatric symptoms and mimic psychiatric diagnoses. When patients have a "strange" presentation of their psychiatric illness, including being out of the usual age range, a fast progression, or an unusual constellation of symptoms, clinicians should pursue a medical work-up and think broadly about other diagnoses that might mimic the psychiatric diagnosis.

Dr. Bhatia provides an overview of common medical and neurologic illnesses that mimic psychiatric diagnoses, including hypothyroidism, delirium, HIV/AIDS, Addison disease, autoimmune encephalitis, temporal lobe epilepsy, frontotemporal dementia, Wilson's disease, and Parkinson's disease.

Summary

Hypothyroidism is an endocrine disease that can mimic depression. The physical symptoms include constipation, edema, dry skin, hair loss, weight gain, and cold intolerance. Individuals with comorbid hypothyroidism and depression report inadequate response to antidepressants, so psychiatrists should check the patient's thyroid-stimulating hormone or refer them to their primary care physician if they suspect hypothyroidism with elevated TSH.

Delirium is a common yet underdiagnosed syndrome that occurs secondary to medical illness and can produce an array of neuropsychiatric symptoms, including psychosis, irritability, and disorganized behaviors, which can lead to misdiagnosis as schizophrenia or mania. Delirium presents as an abrupt change in cognition with disorientation and significantly impaired attention. Hypoactive delirium presents with lethargy, apathy, and decreased alertness, and is often mistaken for depression in the hospital setting. Simple beside tests such as the Confusion Assessment Method can be used to quickly aid in diagnosing delirium.

HIV/AIDS can mimic psychiatric disease through direct effect on the nervous system, opportunistic disease, intracranial tumors, cerebral vascular disease, and medication adverse effects. HIV can mimic depression by causing neurovegetative symptoms; apathy, psychomotor slowing, and working memory deficits are more characteristic of the neuropsychiatric impairment from HIV rather than a primary depressive disorder. In late-stage HIV/AIDS, dementia can cause bizarre behaviors, delusions, and mood disturbance such as euphoria and irritability.

Addison disease is characterized by low blood pressure, hyperpigmentation, nausea, vomiting, weakness, fatigue, hypokalemia, and hyponatremia. Addisonian crisis can present with neuropsychiatric symptoms of delirium, anxiety, agitation, cognitive impairment, and auditory and visual hallucinations.

Autoimmune encephalitis, with anti–N-methyl-D-aspartate receptor encephalitis as the most common type, often masquerades as a primary psychotic symptom. Notable symptoms include subacute onset with fast progression and no clear prodrome, working memory impairment, agitation, or lethargy. Other presenting symptoms include focal neurologic deficits, new-onset or rapidly developing catatonia, fever, headaches, flu-like illness, and autonomic disturbance.

Temporal lobe epilepsy also can mimic a primary psychiatric disorder. The symptoms of seizure-like staring, blinking, lip-smacking, and behavioral arrest are precipitated by a sensation of fear or epigastric sensation and depersonalization, which can lead to misdiagnosis as a panic attack.

Frontotemporal dementia (FTD) can be mistaken for a primary psychiatric diagnosis in the initial stages. Hallmark symptoms include progressive behavioral change with disinhibition and a decline in executive functioning and language skills such as verbal learning and reasoning. FTD is the second most common dementia in people aged younger than 65 years. Patients with FTD struggle to give a history, and often lack a psychiatric history or exposure to psychotropic drugs. Clinicians should maintain a high degree of clinical suspicion for FTD in new-onset psychiatric syndromes in older individuals.

Stroke can lead to poststroke depression and anxiety, apathy, emotional lability, and personality changes. Depression after stroke, occurring hours to days after the insult, is associated with greater cognitive impairment and increased mortality. The diagnosis of poststroke depression is challenging because of impairments in language and cognition after stroke. Apathy can occur separately from depression and diminish recovery.

Wilson's disease results in copper deposits in the brain and liver. The psychiatric symptoms, including psychosis, occur before neurologic changes. Parkinson's disease also can result in depression-like symptoms, given the motor and neurovegetative symptoms from the neurodegeneration. Fatigue, psychomotor slowing with diminished facial expression, postural changes, and sleep disturbance are common conditions that can mimic depression.

References

Carroll VK. Current Psychiatry. 2009 Aug;8(8):43-54.

Welch KA and Carson AJ. Clin Med (Lond). 2018 Feb;18(1):80-7.

Scarioni M et al. Ann Neurol. 2020;87(6):950-61.

Evans DL et al. Neuropsychiatric manifestations of HIV-1 infection and AIDS, in "Neuropsychopharmacology: 5th Generation of Progress." Philadelphia: Lippincott Williams & Wilkins, 2002, pp. 1281-99.

Deng P and Yeshokumar A. Psychiatric Times. 2020 Jan. (37):1.

Kumar A and Sharma S. Complex partial seizure, in "StatPearls [Internet]." Treasure Island, Fla.: StatPearls Publishing, 2020 Jan. (Updated 2020 Nov 20).

Rao V. Neuropsychiatry of stroke. Geriatric Workforce Program. Johns Hopkins Medicine.

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Show notes by Jacqueline Posada, MD, associate producer of the Psychcast; assistant clinical professor in the department of psychiatry and behavioral sciences at George Washington University in Washington; and staff physician at George Washington Medical Faculty Associates, also in Washington. Dr. Posada has no conflicts of interest.

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