When psychiatric symptoms reflect medical conditions

Summary & key facts

This paper explains that many medical and neurological conditions can cause psychiatric symptoms. Doctors should check for things like delirium, infections, seizures, or immune conditions before assuming a purely psychiatric illness. Simple bedside attention tests, a basic physical and neurological exam, routine blood tests, and targeted brain imaging or antibody tests when signs are unusual can help find underlying medical causes.

Key facts:

• A classic case series found that 12% of consecutive psychiatric admissions had a previously unidentified physical illness judged important to the psychiatric presentation.
• People with major psychiatric disorders have a 10–15 year reduction in life expectancy, and most of the extra deaths are from physical (medical) illnesses rather than suicide.
• Delirium should be assumed in medical inpatients with new mental-state disturbance until proved otherwise; it usually has an abrupt onset, a fluctuating course, and impaired attention.
• Hypoactive (quiet) delirium is more common than the agitated (hyperactive) form and can be mistaken for severe depression or withdrawal.
• Impaired sustained attention is a key sign of delirium and can be tested at the bedside with tasks like serial seven subtractions or saying the months of the year backwards; validated tools such as the 4AT are recommended.
• Some immune-mediated brain diseases (for example, limbic encephalitis, including NMDA receptor antibody encephalitis) can present like a first episode of psychosis and may need specific tests (eg antibody assays and targeted imaging).
• The paper advises routine basic screening for new psychiatric presentations: a full physical and neurological exam, cognitive assessment, and basic blood tests; brain imaging is recommended when the presentation is atypical or there are red

Abstract

The brain dysfunction associated with certain medical and neurological conditions can produce essentially any psychiatric symptom. This means there is always a chance that presentations thought to be 'psychiatric' are actually explained by unidentified medical pathology. This paper aims to outline an approach to minimise these missed diagnoses.

Topics

Autoimmune Neurological Disorders and Treatments Obsessive-Compulsive Spectrum Disorders Psychosomatic Disorders and Their Treatments

Categories

Health Sciences Medicine Neurology

Tags

Medicine Psychiatry

Conditions & symptoms

Anxiety Depression Sleep disorder Difficulty focusing Lack of energy or motivation Poor sleep Sadness or low mood