Neurology and Neurosurgery/Anosognosia

Impaired awareness of illness (anosognosia) is a major problem because it is the single largest reason why individuals with schizophrenia and bipolar disorder do not take their medications. It is caused by damage to specific parts of the brain, especially the right hemisphere. It affects approximately 50 percent of individuals with schizophrenia and 40 percent of individuals with bipolar disorder. When taking medications, awareness of illness improves in some patients. Impaired awareness of illness is a strange thing. It is difficult to understand how a person who is sick would not know it. Impaired awareness of illness is very difficult for other people to comprehend. To other people, a person’s psychiatric symptoms seem so obvious that it’s hard to believe the person is not aware he/she is ill. Oliver Sacks, in his book The Man Who Mistook His Wife for a Hat, noted this problem:

It is not only difficult, it is impossible for patients with certain right-hemisphere syndromes to know their own problems …And it is singularly difficult, for even the most sensitive observer, to picture the inner state, the ‘situation’ of such patients, for this is almost unimaginably remote from anything he himself has ever known.