What Are Mild and Major Neurocognitive Disorders?

Major and mild neurocognitive disorders were previously known as dementia. The Diagnostic and Statistical Manual of Mental Disorders now uses the terms major neurocognitive disorder and mild neurocognitive disorder.

Everyone experiences forgetfulness or occasional clumsiness, and short bouts of depression or anxiety during periods of stress are also common. But if a person is experiencing noticeable memory loss, difficulty communicating, significant problems handling daily tasks, confusion, personality changes, and mood or behavioral symptoms – he or she may have a neurocognitive disorder. 

Major and mild neurocognitive disorders can occur with Alzheimer’s disease, degeneration of the brain’s frontotemporal lobe, Lewy body disease, vascular disease, traumatic brain injury, HIV infection, prion diseases, Parkinson’s disease, Huntington’s disease, or another medical condition, or they can be caused by a drug or medication.

Mild and Major Neurocognitive Disorders Signs and Symptoms

Major neurocognitive disorder is classified by the following symptoms:

• Evidence of significant cognitive decline from a previous level of performance in one or more of the following cognitive areas:

• Attentiveness, especially when multitasking
• Planning, organizing and decision-making
• Learning
• Memory
• Language
• Perceptual-motor (translating perception into action)
• Ability to comprehend social cues and/or behave appropriately in social situations
• Concern from the individual, a friend or family member, or his or her physician that there has been a significant decline in cognitive function
• A substantial impairment in cognitive performance documented by standardized neuropsychological testing or another clinical assessment

These cognitive deficits interfere with independence in everyday activities, do not occur exclusively in the context of a delirium and are not better explained by another mental disorder. In some cases, these symptoms are accompanied by behavioral disturbances like psychotic symptoms, mood conditions, agitation and/or apathy, and in other cases, these behavioral elements are not present.

Mild neurocognitive disorder is classified by the following symptoms:

• Evidence of modest cognitive decline from a previous level of performance in one or more of the following cognitive areas:
• Attentiveness, especially when multitasking
• Planning, organizing and decision-making
• Learning
• Memory
• Language
• Perceptual-motor (translating perception into action)
• Ability to comprehend social cues and/or behave appropriately in social situations
• Concern from the individual, a friend or family member, or his or her physician that there has been a mild decline in cognitive function
• A modest impairment in cognitive performance documented by standardized neuropsychological testing or another clinical assessment

These cognitive deficits do not interfere with independence in everyday activities, do not occur exclusively in the context of a delirium and are not better explained by another mental disorder. In some cases, these symptoms are accompanied by behavioral disturbances like psychotic symptoms, mood conditions, agitation and/or apathy, and in other cases, these behavioral elements are not present.

Mild and Major Neurocognitive Disorders Diagnosis

Diagnosing major or mild neurocognitive disorder requires a thorough physical, psychological and neurological evaluation. Your physician will use the criteria for neurocognitive disorders listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, to determine if your symptoms indicate the condition.

Diagnostic tests include:

Brain scans: A CT scan or MRI can help your physician determine if a specific brain condition is causing your symptoms, such as a stroke, a tumor or hydrocephalus (a buildup of too much cerebrospinal fluid). A PET scan can show patterns of brain activity and identify if an amyloid protein found in Alzheimer’s disease is present.

Cognitive and neuropsychological tests: These tests measure skills such as memory, orientation, reasoning and judgment, language and attention.

Lab tests: Blood tests can detect health issues that can affect brain function, such as a vitamin B-12 deficiency or an underactive thyroid. Spinal fluid may also be examined for signs of infection, inflammation or markers of some degenerative diseases.

Neurological evaluation: Your physician will evaluate your memory, language skills, visual perception, attention, problem-solving, movement, senses, balance, reflexes and more.

Physical examination: A physician will perform a physical exam and ask questions about your health to determine if your symptoms could be linked to an underlying physical health problem or medication side effect.

Psychiatric evaluation: A behavioral health physician can determine whether depression or another mental health condition is contributing to your symptoms.

Causes of Mild and Major Neurocognitive Disorders

Neurocognitive disorders can be reversible or irreversible, depending on their cause. They are characterized by damage to nerve cells in the brain. Symptoms vary depending on the area of the brain affected.

Nonreversible causes include:

• Alzheimer’s disease – The most common cause of neurocognitive disorders in people over the age of 65, Alzheimer’s disease often presents with protein plaques and tangles on the brain. In some cases, there is a genetic component.
• Creutzfeldt-Jakob disease – This rare brain disorder may be caused by an abnormal form of protein. It can be inherited or caused by exposure to diseased brain or nervous system tissue.
• Frontotemporal degeneration – Characterized by the breakdown of nerve cells in the frontal and temporal lobes of the brain, frontotemporal degeneration typically causes people to experience personality, behavior and language symptoms. 
• Huntington’s disease – This genetic disease causes certain nerve cells in the brain and spinal cord to waste away. Symptoms, including a severe decline in cognitive skills, usually appear around age 30 or 40.
• Lewy body disease – In this second-most common type of progressive neurocognitive disorder, protein deposits called Lewy bodies develop in nerve cells in the brain regions involved in thinking, memory and movement.
• Parkinson’s disease – This chronic, progressive movement disorder can also feature neurocognitive symptoms. 
• Repeated traumatic brain injury – Repetitive head trauma, which may be frequently experienced by boxers, football players or soldiers, can lead to neurocognitive disorders. 
• Vascular disease – In many cases, neurocognitive disorders occur as a result of damage to the vessels that supply blood to the brain. 

Potentially reversible causes include:

• Hypoxia – When the brain doesn’t get enough oxygen, neurocognitive symptoms may appear. This can be caused by carbon monoxide poisoning, heart attack and other issues.
• Infections and immune disorders – Fevers and other immune processes caused by the body’s attempt to fight off an infection can lead to neurocognitive symptoms, as well as conditions in which the immune system attacks nerve cells – like multiple sclerosis.
• Medication reactions – Certain reactions or drug interactions can result in neurocognitive symptoms.
• Metabolic and endocrine problems – Thyroid problems, low blood sugar, too little or too much sodium or calcium, or impaired vitamin B-12 absorption can lead to cognitive symptoms and personality changes.
• Normal-pressure hydrocephalus – Enlarged ventricles in the brain can cause walking problems, urinary issues and memory loss.
• Nutritional deficiencies – Dehydration or deficiencies in vitamins B-1, B-6 or B-12 can cause neurocognitive symptoms.
• Poisoning – Exposure to high levels of heavy metals like lead, and other poisons, pesticides, or excessive alcohol or recreational drugs can cause neurocognitive symptoms. 
• Subdural hematoma – Bleeding between the brain and its covering, which can occur from a fall, may result in neurocognitive symptoms.
• Tumors – Rarely, brain tumors can cause neurocognitive symptoms.

Risk Factors

Certain risk factors for neurocognitive disorders cannot be changed. These include:

Age: The risk for both major and mild neurocognitive disorder rises after age 65.

Down syndrome: Many people with Down syndrome develop early-onset Alzheimer’s disease by middle age.

Family history: Certain genetic mutations and/or several members of the same family developing neurocognitive disorders may increase your risk. But, many people with family histories don’t develop the disorder, and many people who do don’t have a family history.

Mild neurocognitive disorder (risk factor for developing major neurocognitive disorder): This involves some thinking and memory difficulties without loss of daily function.

Other risk factors for developing neurocognitive disorders can be changed:

Cardiovascular risk factors: High blood pressure, high cholesterol, a buildup of fats in your artery walls (atherosclerosis) and obesity all increase your risk of developing a neurocognitive disorder, especially one caused by vascular disease.

Depression: Though not fully understood, depression late in life can influence development of a neurocognitive disorder.

Diabetes: This elevated blood sugar condition, especially if poorly controlled, increases your risk of developing a neurocognitive disorder.

Excessive alcohol consumption: Drinking large amounts of alcohol might raise your risk of a neurocognitive disorder. Some studies have shown that moderate amounts of alcohol might have a protective effect.

Smoking: Smoking might increase your risk of developing neurocognitive conditions and vascular diseases.

Sleep apnea: People who have episodes where they frequently stop breathing while asleep may experience (often) reversible memory loss.

Prevention

Major and mild neurocognitive disorders cannot be prevented, but certain lifestyle changes can reduce your risk. Keeping your mind active through puzzles, games and memory training; staying physically and socially active; eating a healthy diet; avoiding cigarettes; getting enough vitamin D and lowering your blood pressure (if high) can all help.

Mild and Major Neurocognitive Disorders Prognosis

Some cases of neurocognitive disorder – especially if due to vitamin deficiency, infections, metabolic problems, one-time injuries and temporary hypoxia – may be reversible. Others are nonreversible and progressive, but treatments may help manage symptoms and maintain quality of life for months or years. 

Treatment

Most nonreversible, progressive types of neurocognitive disorders are incurable. But, certain treatments and coping strategies can help manage symptoms.

Lifestyle Remedies

Friends, family members or caregivers can help people with neurocognitive disorders stay as physically and socially active as possible, communicate more simply and effectively, establish rituals and calendars to help limit disorientation and enhance memory, and plan for the future. These steps may slow symptom progression, make the person feel more comfortable and in control, and reassure him or her of the support system that’s available. 

Medications

Cholinesterase inhibitors boost levels of a chemical messenger involved in memory and judgment. They are typically prescribed for Alzheimer’s disease but may also be used to manage other neurocognitive disorders. Memantine may be prescribed to regulate the activity of glutamate, another chemical messenger involved in brain functions like learning and memory. Other medications can help ease symptoms like depression, agitation or sleep disturbances.

 Nonmedical Therapies

Nonmedical approaches include:

• Environmental modification: Reducing clutter and noise and removing unsafe objects or environmental hazards can make it easier for people with major neurocognitive disorder to focus and function.
• Occupational therapy: An occupational therapist can help with home modifications and teach coping strategies. This can help prevent accidents, manage behavior, and prepare someone for the progression of symptoms.
• Task modification: Breaking daily tasks into smaller, easier steps and focusing on success, not failure can help people with neurocognitive disorders. Structure and routine also help reduce confusion.
• Relaxation methods: Aromatherapy, as well as art, massage, music and pet therapies may help ease agitation.

Complications

Complications of major neurocognitive disorders include:

• Inadequate nutrition due to a disinterest in food or inability to chew and swallow
• Inability to perform daily tasks
• Personal safety challenges, associated with driving, cooking, walking alone and other activities
• Pneumonia due to choking or aspiration of food
• Death, typically a result of infection in late-stage major neurocognitive disorder or as a result of the causative factor (stroke, Parkinson’s disease, etc.)