Major and Mild Neurocognitive Disorders

What are Major and Mild Neurocognitive Disorders?

Major and mild neurocognitive disorders are a group of conditions or diseases that affect a person’s thinking, memory, reasoning, personality or mood, coordination, behaviors, and social abilities. Neurocognitive disorders are grouped into major or mild disorders, which are differentiated by being either a degenerative or non-degenerative disease or illness. The decline in mental functioning significantly affects a person’s ability to function at a normal level in their daily life.

There are several causes for neurocognitive disorders, with Alzheimer’s being the most common. Depending on the cause, some neurocognitive disorders are degenerative, while others are non-degenerative. A degenerative neurocognitive disease means that the disease is not curable or reversible, and the disease will continue to progress and cause degeneration of the brain.

Signs and Symptoms

Signs and symptoms of neurocognitive disorders will vary, depending on the cause. Common symptoms include:

Cognitive changes

  • Memory loss 
  • May find it difficult to find or recall words
  • Difficulties communicating
  • Issues with visual spatial skills, such as getting lost or confused while driving
  • Challenges with problem-solving or reasoning
  • Difficulties with planning and organizing
  • Issues dealing with complex tasks
  • A loss of coordination or motor skills
  • Disorientation and confusion
Psychological changes
  • Depression
  • Anxiety
  • Personality changes
  • Atypical inappropriate behaviors
  • Agitation
  • Paranoia
  • Hallucinations


Neurocognitive disorders occur when parts of your brain that impact memory, learning, decision-making, and language are affected by disease, infection, or injury. The disease or injury causes damage to the nerves and nerve connections in the brain.

Depending on the extent or area of the damage, symptoms will vary between individuals. The most common cause of neurocognitive disorders is Alzheimer’s disease. There are several other causes of neurocognitive disorders that can be degenerative or non-degenerative diseases. Other causes include:

Degenerative diseases

  • Vascular dementia
  • Dementia with Lewy bodies
  • Frontotemporal dementia
  • Mixed dementia
  • Parkinson’s disease
  • Huntington’s disease
  • Prion disease
  • Creutzfeldt-Jakob disease
Non-degenerative conditions
  • People who are under the age of 60 are more likely to develop neurocognitive disorders due to infection or injury. These types of neurocognitive disorders tend to be non-degenerative and can be reversible. Causes include:

  • Concussions
  • Traumatic brain injury (TBI) that leads to bleeding and swelling of the brain, or in the space around the brain
  • Infections and immune disorders (multiple sclerosis, meningitis, encephalitis, or septicemia)
  • Drug or alcohol abuse
  • Metabolic or endocrine abnormalities (thyroid issues, hypoglycemia, too much or too little of sodium or calcium, etc.)
  • Vitamin or nutritional deficiencies 
  • Medication side effects
  • Brain tumors
  • Normal-pressure hydrocephalus

Risk Factors

Several risk factors contribute to the development of neurocognitive disorders. Some factors, such as age, are uncontrollable. However,  some risk factors can be managed and will decrease your risk of developing a neurocognitive disorder. Risk factors include:

Risk factors that are unchanging

  • Age. Neurocognitive disorders are not a normal part of aging; however, your risk increases as you age. Young people can also develop neurocognitive disorders.
  • Family history. Research has found that genetic factors may contribute to developing neurocognitive disorders. However, not all people who have a family history of neurocognitive disorders go on to develop a neurocognitive disorder. There are genetic tests that can determine whether you have a genetic mutation that would increase your risk.
  • Down syndrome. By middle age, it is common for people with Down syndrome to develop early onset Alzheimer’s.
Risk factors that can be managed or changed

  • Diet and exercise. Studies have found that a lack of exercise can result in an increased risk of developing a neurocognitive disorder. Although specific foods have not been proven to reduce the risk of developing a neurocognitive disorder, eating an unhealthy diet has shown a greater prevalence of developing a neurocognitive disorder
  • Excessive alcohol use. Excessive alcohol consumption is known to cause brain changes. Studies that are more recent indicate that excessive alcohol consumption can increase the risk of developing a neurocognitive disorder, particularly early onset dementia.
  • Cardiovascular risk factors. High blood pressure (hypertension), high cholesterol, buildup of fats in your artery walls, and obesity can create an increased risk in developing a neurocognitive disorder.
  • Diabetes. Specifically, poorly managed diabetes can increase the risk.
  • Smoking. Studies have shown it may increase your risk of developing a neurocognitive disorder and blood vessel diseases.
  • Depression. Late-life depression may indicate a developing neurocognitive disorder.
  • Vitamin and nutrition deficiencies
  • Air pollution. Studies have found that air pollution exposure can increase your risk.
  • Head trauma. Studies have demonstrated that people who have had a severe traumatic brain injury (TBI) have a greater risk of developing a neurocognitive disorder over the age of 50. The risk increases for more severe or multiple TBI’s. 
  • Sleep disturbances. Sleep apnea and other sleep disorders have been known to increase the risk of developing a neurocognitive disorder.
  • Medications that have adverse effects on memory. Speak with your doctor before taking any sleep aid medications, or urinary urgency medications, as these have been shown to impact memory.


Neurocognitive disorders can lead to several complications, including personal safety issues and death. Complications include:
  • Poor nutrition
  • Pneumonia
  • Inability to perform self-care tasks (personal hygiene, taking medications, etc.)
  • Personal safety issues (driving, cooking, living alone, etc.)
  • Death (late-stage disease can lead to coma or death, typically from infection)


Although preventative measures are not full proof, they can help decrease your risk from developing a neurocognitive disorder or may be able to delay or slow down its development. There are several preventative measures a person can take, that help keep your cholesterol, blood pressure, and blood sugar levels in a healthy range. Preventative measures include:

  • Maintaining a healthy diet and weight (doctors recommend the Mediterranean diet, which is rich in whole grains, fruits and vegetables, beans, nuts, seeds, fish, olive oil)
  • Exercise (150 minutes a week, or 30 minutes 5 days a week)
  • Quit smoking
  • Limit alcohol consumption
  • Manage your cardiovascular health
  • Make sure your vitamins and nutrients are at an appropriate level
  • Be socially active and connected
  • Stimulate your brain (puzzles, games, brainteasers, reading, etc.)
  • Get quality sleep
  • Treat hearing loss
  • Stay on top of other health conditions


Diagnosing a neurocognitive disorder can be difficult. There are many other conditions and diseases that have similar symptoms. To begin the process of diagnosing, your healthcare provider will take a thorough medical history, including a family history of any neurocognitive disorders.

They will also ask about current medications and the symptoms you have been experiencing. Additionally, your healthcare provider will order lab tests, imaging tests, and neurocognitive testing to help rule out conditions and make an appropriate diagnosis.

  • Laboratory tests. These types of tests can rule out other conditions or diseases, such as underactive thyroid, infection, auto-immune disorders, inflammation, or other vitamin deficiencies. 
  • Imaging tests. Brain imaging, such as MRI’s and CT scans are used to detect any sign of stroke, tumor, bleeding, or fluid on the brain. An FDG-PET scan is used to determine brain functioning and cognitive decline by detecting patterns of glucose absorption by brain tissue.
  • Neurocognitive testing. This type of testing is used to assess and evaluate cognitive skills and abilities such as memory, learning, reasoning, problem-solving, judgment, planning, and language.
  • Psychiatric evaluation. A mental health professional will evaluate for any mood, personality, or behavioral changes that may indicate a neurocognitive disorder.


Some neurocognitive disorders are reversible, depending on the cause. However, most neurocognitive disorders are not curable; however, there have been some medications and treatments that have helped manage symptoms and slow progression.

There continues to be ongoing research and clinical trials working to develop medications that would slow or stop the cognitive decline apparent in neurocognitive disorders. Currently there are no medications that stop cognitive decline in major neurocognitive disorders. Please consult with your healthcare providers to discuss medications that may help treat your symptoms.