The differences between delirium and dementia

June is Alzheimer’s and Brain Awareness Month, and the piece below is one of several this month to educate the public about these critical topics.DELIRIUM and dementia are two conditions that can affect older adults but they are often misunderstood or confused with each other. While they may share some similarities, they are distinct conditions with different causes, symptoms, and treatments. Let’s assess the key differences between delirium and dementia to shed light on these important medical events.What is delirium?Delirium is a sudden and severe change in mental function that can occur in people of all ages, but it is more common in older adults. It is often triggered by an underlying medical condition, such as an infection like a urinary tract infection, medication side effects, or dehydration. Delirium can develop rapidly, within hours or days, and is characterised by fluctuating levels of consciousness, confusion, disorientation (ie, difficulty with knowing date, time, where you are located), and altered perception. Individuals experiencing delirium may also exhibit agitation, hallucinations, and disturbed sleep patterns. It is considered a medical emergency and requires prompt evaluation and treatment to identify and address the underlying cause.Understanding dementiaDementia, on the other hand, is a progressive neurological condition characterised by a decline in cognitive function severe enough to interfere with daily life. Alzheimer’s disease is the most common cause of dementia but there are other types as well, including vascular dementia, Lewy body dementia, and frontotemporal dementia. Unlike delirium, which often has a sudden onset, dementia develops gradually over time and worsens progressively. Memory loss, impaired judgement, difficulty with communication, and changes in mood and behaviour are common symptoms of dementia. While there is currently no cure for dementia, treatments and interventions can help manage symptoms and improve quality of life.Key differencesOnset and duration: Delirium typically has a sudden onset and may last for hours, days, or weeks, whereas dementia develops slowly over months or years and worsens over time.Causes: Delirium is often triggered by an underlying medical condition such as an infection or medication side effects whereas dementia is caused by progressive brain changes associated with specific diseases, such as Alzheimer’s.Symptoms: Delirium is characterised by fluctuating levels of consciousness, confusion, and disorientation while dementia is marked by memory loss, impaired thinking skills, and changes in behaviour.Reversibility: Delirium is often reversible once the underlying cause is identified and treated, whereas dementia is generally irreversible and requires ongoing management and support.Treatment: Treatment for delirium focuses on addressing the underlying medical condition and providing supportive care to manage symptoms, while treatment for dementia aims to slow disease progression, manage symptoms, and improve quality of life.While delirium and dementia may share some similarities in symptoms, they are distinct conditions with different causes, courses, and treatments. Understanding the differences between these two conditions is essential for accurate diagnosis and appropriate management. If you or a loved one are experiencing changes in mental function, it is important to seek medical evaluation to determine the underlying cause and receive timely intervention and support. With proper care and understanding, individuals affected by delirium and dementia can receive the assistance they need to maintain their health and well-being.Robiann Broomfield is currently completing her PhD in clinical psychology with a specialisation in neuropsychology. In addition, she is also completing her clinical internship at Baylor College of Medicine/TIRR Memorial Hermann Hospital in rehabilitation psychology and neuropsychology. Starting in September she will begin a fellowship at Harvard Medical School in neuropsychology.