Cognitive disorders, or as the DSM-5 now refers to them, neurocognitive disorders, are conditions that have the effect of drastically altering or changing a person's thinking processes. Most neurocognitive disorders involve a significant change in a person's ability to learn and remember information. They also disrupt other thinking processes such as:
- the ability to reason
- to communicate with others
- to be able to visualize objects through space
- to pay attention to things,
- and more.
There are many conditions that can result in a person developing a neurocognitive disorder. Some of these conditions can be reversed and others cannot be reversed currently. However, researchers hope that in the future treatments may reverse the effects of some of these conditions to some extent.
Dementia is a term that refers to a gradual or sudden loss of a person's cognitive abilities. This can be due to some medical condition or even a psychological problem. Some of these conditions can be reversed fully or partially. Therefore, any changes that happened in the person's thinking processes may also be reversed, at least partially, with treatment. Other conditions may produce damage to the brain that cannot be reversed. The change in the person's thinking will not get better with treatment. In many of these conditions the disorder may even get worse as the disease progresses.
Some examples of forms of dementia that are not reversible currently include:
- Alzheimer's disease.
- Lewy body dementia.
- Dementia associated with Huntington's disease.
- Frontotemporal dementia.
- The dementia associated with an HIV infection.
- Others such as the dementia associated with a vascular problem or a head injury might lead to cognitive dysfunction that can be permanent (see the description of these conditions below).
In some cases, treatment can slow down the rate of the neurocognitive disorder in Alzheimer's disease or other dementias, but the problems with thinking cannot be reversed. However, in certain types of conditions that can create these disorders the condition can be corrected or reversed and the changes in thinking that happen may also be changed or reversed. In many cases this depends on how severe the condition is or how early doctors can identify and then treat the condition to reverse it.
Some conditions that can produce neurocognitive disorders that may be reversed are:
Depression may produce a neurocognitive disorder. The term pseudodementia is often used to refer to a dementia-like state that happens in some people who have very severe depression. If the depression can be treated, then the severity of the neurocognitive disorder associated with the depression will often be reversed.
Other neurocognitive disorders that are the result of emotional factors such as certain types of amnesia (memory loss without a loss of other thinking capabilities that happen because of an emotional problem or psychological disorder may be reversible if the emotional disturbance can be treated.
Certain forms of delirium. Delirium refers to a neurocognitive condition where a person becomes confused and cannot fully make sense of their environment. Delirium may be mistaken for dementia in some people. In many cases if doctors can find what caused the delirium and treat the cause, then the dysfunction may be reversed. There are many conditions that can cause delirium such as an infection, severe malnutrition, a medical condition, a reaction to drugs or medications, and even problems with the person's metabolism.
Neurocognitive disorders associated with a vascular problem. This is a problem or a condition that affects the person's veins and arteries such as a stroke. This condition may be reversible. The problems with thinking that happen from having a stroke may or may not be reversible depending on the seriousness of the stroke and the amount of damage that the stroke has inflicted on the brain. Very often strokes or damage to the veins and arteries in the brain that are the result of a process that has taken a long time to develop result in more permanent damage than strokes that develop suddenly. However, this is not always the case. The location of the stroke can also be important in determining if the cognitive dysfunction is reversible or permanent.
Neurocognitive disorders associated with a head injury may or may not be reversible. Depending on how severe the head injury is, the problems with thinking that the person has afterwards may be reversed with time and with treatment, or may not fully be reversed even with treatment.
Neurocognitive disorders associated with the use of drugs or medications. The use of certain types of illegal drugs such as cocaine and heroin or reactions to certain types of medications can result in a neurocognitive disorder. The neurocognitive disorder associated with the use of drugs or medications may happen because of an overdose, side effects of the drugs, or long-term usage of the substance. Depending on the amount of damage to the brain that has happened in these situations the changes in the person's thinking may or may not be permanent.
In the above cases the two general conditions that often determine if a neurocognitive disorder can be reversed are:
- the severity of the neurocognitive disorder
- how fast doctors can identify the cause and treat it.
When a neurocognitive disorder is very severe as may happen with some strokes or head injuries, the cognitive dysfunction may not be reversible under any circumstances. In cases where doctors can identify the causes before severe damage can be done to the brain, treatment might reverse the problems with thinking that the condition has produced.