Brian Steinhart’s Best Case Ever on Organic vs Psychiatric Illness on EM Cases

Sometimes what initially appears to be a psychiatric illness turns out to be an organic illness, and vise versa. In our assessment of the patient with altered behaviour, it is critical to drill down and dissect apart the type of hallucinations a patient might be displaying, whether the demented patient is simply suffering from worsening dementia or alternatively has acute delirium (which carries a high mortality rate), and whether their somatic complaints might be due to depression or a psychotic psychiatric illness. In anticipation of our upcoming episode on Medical Clearance of the Psychiatric Patient Dr. Brian Steinhart tells the story of his Best Case Ever, reminding us of some of the clinical clues that can help us in our approach to the patient with altered behaviour, so that we avoid misdiagnosing a psychiatric illness with an organic one, or even worse, an organic illness with a psychiatric one…

Published August 2016 by Anton Helman

Differentiating Delirium, Dementia & Depression in Organic vs Psychiatric Illness

Delirium is the acute and fluctuating onset of in-attention, with disorganized thinking, and/or altered level of awareness. Unlike dementia (which progresses slowly) delirium happens acutely. In the elderly, 70% of delirium is initially “hypoactive,” which can delay its detection in the ED.

Delirium is a very serious presentation, which always has an underlying medical cause. Length of stay in hospital, and in-hospital mortality increases twofold in patients diagnosed with delirium, and delirium is not always reversible. Always assess the baseline functional status of elderly patients, and be suspicious of any acute decline.

organic vs psychiatric illness


Visual vs Auditory Hallucinations

Generally speaking, auditory hallucinations are more indicative of a psychiatric illness where as visual hallucinations are more indicative of an organic illness. While about 15% of patients with schizophrenia are said to experience visual hallucinations, these tend to occur in those schizophrenics with severe illness in addition to auditory hallucinations.

Visual hallucinations can occur in a myriad of organic illnesses and ingestions from LSD to Creutzfeldt-Jakob disease to Delirium Tremens to (my favourite) Anton’s Syndrome.


Dr. Helman and Dr. Steinhart have no conflicts of interest to declare.



Teeple RC, Caplan JP, Stern TA. Visual hallucinations: differential diagnosis and treatment. Prim Care Companion J Clin Psychiatry. 2009;11(1):26-32. Abstract

Fong TG, Davis D, Growdon ME, Albuquerque A, Inouye SK. The interface between delirium and dementia in elderly adults. Lancet Neurol. 2015;14(8):823-832. Full Text


FOAMed Resources

EM Cases Episode 34 on Geriatric Emergencies with Don Melady and Jaques Lee

GEMCast on Diagnosing and Managing Delirium in Older Adults