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What are the three categories of cognitive disorders?

Cognitive disorders are conditions that affect an individual’s ability to think, reason, remember, and perform daily tasks. These disorders can have a significant impact on a person’s quality of life and their ability to function independently. Understanding cognitive disorders is crucial for healthcare professionals, caregivers, and society as a whole. In this blog post, we will explore the three categories of cognitive disorders as outlined in the DSM-5 and discuss their characteristics, causes, symptoms, and management.

Overview of Cognitive Disorders

In the previous edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), cognitive disorders were classified into four categories: delirium, dementia, amnestic disorders, and other cognitive disorders. However, in the current edition, DSM-5, these categories were streamlined into three: delirium, mild neurocognitive disorder (NCD), and major NCD.


Delirium is a temporary and acute cognitive disorder characterized by a sudden change in mental status, confusion, disorientation, and difficulty focusing attention. It is often caused by underlying medical conditions, medication side effects, or substance withdrawal. Delirium can occur in people of all ages but is more common in older adults. Early recognition and management of delirium are essential to prevent further complications.

Causes and Risk Factors

Delirium can result from various factors, including infections, metabolic imbalances, medication interactions, and pre-existing cognitive impairment. Older age, history of cognitive impairment or dementia, multiple comorbidities, and certain medications are among the risk factors for developing delirium.

Symptoms and Diagnosis

The symptoms of delirium vary but commonly include confusion, agitation, hallucinations, fluctuating attention, and disrupted sleep patterns. A thorough medical evaluation, physical examination, laboratory tests, and cognitive assessments are necessary to diagnose delirium accurately.

Treatment and Management

Managing delirium involves addressing the underlying causes and providing supportive care. This may include adjusting medications, treating infections, optimizing hydration and nutrition, and ensuring a calm and familiar environment. In severe cases, medication interventions may be necessary to manage agitation or hallucinations.

Mild Neurocognitive Disorder (NCD)

Mild neurocognitive disorder (NCD) is a condition characterized by mild cognitive impairment that is noticeable but does not significantly interfere with daily functioning. It is often a precursor to major NCD or dementia. Early detection of mild NCD can help in implementing interventions to slow down its progression.

Causes and Risk Factors

The causes of mild NCD can be multifactorial, including medical conditions such as cardiovascular disease, neurodegenerative disorders, and certain lifestyle factors like chronic stress, poor diet, and sedentary lifestyle. Advanced age, family history of dementia, and genetic predispositions are also considered risk factors for developing mild NCD.

Symptoms and Diagnosis

The symptoms of mild NCD include difficulties with memory, language, attention, and executive functions. These symptoms are noticeable to both the individual experiencing them and those around them. Diagnosis involves a thorough medical evaluation, neurological examination, neuropsychological testing, and brain imaging to rule out other causes of cognitive impairment.

Treatment and Management

Management of mild NCD focuses on lifestyle modifications, such as engaging in mentally stimulating activities, maintaining a balanced diet, regular physical exercise, and managing chronic conditions effectively. Cognitive training programs and supportive therapies can also be beneficial in managing symptoms and improving cognitive function.

Major Neurocognitive Disorder (NCD)

Major neurocognitive disorder (NCD), previously known as dementia, is a progressive cognitive decline that significantly impairs an individual’s ability to function independently. It is characterized by severe memory loss, language difficulties, impaired judgment, and personality changes. Major NCD often requires long-term care and support.

Causes and Risk Factors

The causes of major NCD are diverse and can include neurodegenerative diseases like Alzheimer’s disease, vascular disorders, Parkinson’s disease, and traumatic brain injuries. Aging is the most significant risk factor for major NCD, with the incidence increasing significantly after the age of 65. Other risk factors include genetics, family history, and lifestyle factors.

Symptoms and Diagnosis

The symptoms of major NCD are more severe than mild NCD and often significantly impair an individual’s ability to perform daily tasks. Memory loss, confusion, difficulty with language and communication, behavioral changes, and disorientation are common symptoms. Diagnosis involves comprehensive medical evaluation, neuropsychological testing, neuroimaging, and clinical assessments.

Treatment and Management

Managing major NCD involves a multidisciplinary approach to address the cognitive, physical, and emotional needs of individuals. Treatment options are focused on symptom management, support services, cognitive rehabilitation, and strategies to enhance quality of life. Caregiver education and support are also crucial for the overall well-being of both the individual and their caregiver.

Other Cognitive Disorders

In addition to the three main categories mentioned above, the DSM-5 recognizes other cognitive disorders that may not fit precisely into these categories. These disorders include cognitive disorders due to medical conditions, substance-induced cognitive disorders, and cognitive disorders not otherwise specified.

These additional cognitive disorders can arise from conditions such as traumatic brain injury, HIV infection, epilepsy, or substance abuse. Each disorder has its specific diagnostic criteria and treatment approaches, which may involve managing the underlying condition, medication interventions, or supportive care.


Cognitive disorders have a significant impact on individuals, their families, and society as a whole. Understanding the three categories of cognitive disorders outlined in the DSM-5 is crucial for early detection, accurate diagnosis, and appropriate management. Delirium, mild NCD, and major NCD differ in their severity and prognoses, but all require comprehensive care and support. Continued research and advancements in treatment strategies will play a crucial role in improving the quality of life for individuals affected by cognitive disorders.


  1. Cognitive Disorders – an overview | ScienceDirect Topics
  2. Cognitive Disorder Diagnosis & Treatments | Mount Sinai
  3. Neurocognitive disorder: MedlinePlus Medical Encyclopedia
  4. Chapter 15 Cognitive disorders Flashcards
  5. Cognitive disorder – Wikipedia