Anosognosia – Definition, Videos, and Stats

Causes of anosognosia in SMI

Anosognosia was first discovered by physicians who noticed that after a traumatic brain injury or a stroke, some patients were unable to recognize changes in their abilities, such as being unable to move one side of their body. Anosognosia can also occur in people with Alzheimer’s disease. Anosognosia is thought to be caused by changes or differences in brain structure due to brain damage.

Our understanding of the relationship between anosognosia and various parts of the brain is still evolving. However, based on current research, there are several brain structures that may be related to anosognosia, including the frontal lobe, which is an important part of the brain for cognitive skills like memory, problem solving, and metacognition. Accordingly, damage to the frontal lobe may make it difficult for people with psychosis to make sense of their past symptoms and experiences, accurately compare their current abilities with what they could do in the past, and understand the beliefs of family members, friends, and care providers. Low insight into having an illness has been associated with smaller prefrontal grey matter volume in schizophrenia patients and higher frontal lobe dysfunction.

Several studies have found that people with schizophrenia experience changes in their frontal lobe over the course of their illness, including decreased grey matter in the frontotemporal lobe, decreased white matter and increased cerebrospinal fluid in the frontal regions of the brain, and decreased grey matter in orbital-frontal regions of the brain. These structural changes were more dramatic for those who had a longer duration of untreated psychosis. People with schizophrenia and anosognosia have also been found to have less gray matter than people with schizophrenia who do not have anosognosia in other regions of the brain.

Another key area implicated in anosognosia is the right hemisphere of the brain. This relationship has been found among stroke survivors, people who have experienced traumatic brain injury, people with dementia, and people with SMI.

Anosognosia and denial

Crucially, anosognosia is different from denial of having a mental illness. To illustrate how delusions are experienced by people who have anosognosia, Dr. Xavier Amador provides the following example based on his clinical experience:

“Imagine I told you that you did not live where you live. You might laugh and tell me to stop joking around. But what if I produced a restraining order from a court that ordered you to stay away from what you told me was your home address? Taking it further, let’s say you live with other people, perhaps members of your family, and you saw that they had signed off on this court order. What would you think? Then, imagine that you then called them to ask why they’d signed off, and they said something like, ‘You seem like a nice person, but if you keep coming around here, we are going to call the police. You don’t live here, and we don’t want to press charges, but we will if you put us in that position. Please stop calling us. You need help!’ If you can imagine something like this happening to you, then you have idea of what it is like for someone with a mental illness to have a delusion and anosognosia.”

It is also important to consider cultural differences in the understanding of mental illness when determining if a person has anosognosia. The idea that SMI is a biological disease is not present in all cultures. One review of studies proposed that a person should be determined to have insight if they know there has been a change in their body or mind that has impacted their ability to function and acknowledge the need to restore their previous abilities. Using this definition, a person could be determined to have insight even if they do not believe their symptoms represent an illness. The author notes that a person with delusional explanations for their symptoms (i.e., those that differ from family and local cultural explanations) would not be considered to have insight using this definition.

Anosognosia and capacity to make informed medical decisions

It has been estimated that up to 25% of psychiatric inpatients may not have the capacity to make informed medical decisions because of their illness. A 2025 article from CNS Spectrums explored the legal complexities of informed consent among patients with anosognosia and schizophrenia. The author proposed that a person should not be considered competent to make informed medical decisions when lack of insight has lasted more than six months, does not change even when presented with evidence, and when the explanations offered to explain situations or symptoms of the illness are objectively false. However, the authors also note that to protect patient autonomy, this lack of insight must also have been documented for at least six months and a medical professional must be willing to testify that the patient’s lack of insight is a symptom of their illness and not denial.

The insight paradox

Improvements in insight are associated with a number of positive outcomes for people with SMI including fewer hospital readmissions, improved functioning, and decreased likelihood of violence. However, higher levels of insight have also been associated with higher suicide risk, depression, self-stigma, emotional distress, and lower levels of hope.

The association between better insight and higher psychological distress may exist because people with anosognosia are protected from the stigma attached to an SMI diagnosis because they do not believe they have an illness. They may also be protected from the distress of experiencing psychotic symptoms when they cannot perceive a difference between their symptoms and reality. Improved insight into illness may increase suicidality when a better understanding of illness-induced life changes causes increased feelings of self-stigma, hopelessness, and depression.

This relationship between anosognosia and suicidality has been called the ‘insight paradox.’ To mitigate this risk, it is important to provide patients with psychosocial interventions that help to reduce internalized stigma, maintain hope, and process traumatic experiences, especially as levels of insight improve.