Anosognoisa -- An Explanation

Anosognosia is a condition in which a person who suffers disability due to brain injury seems unaware of or denies the existence of his or her handicap. The word comes from the Greek words "nosos" disease and "gnosis" knowledge.

Although largely used to describe unawareness of impairment after brain injury or stroke [described in detail below to give a fuller picture], the term 'anosognosia' is occasionally used to describe the lack of insight shown by some people who suffer from psychosis, and who therefore do not have the insight to recognize that they suffer from a mental illness.

On reviewing the applicable literature, one researcher concluded that:

"Poor insight in schizophrenia is associated with poorer medication compliance, poorer psychosocial functioning, poorer prognosis, increased relapses and hospitalization and poorer treatment outcomes."

The three kinds of insight that are most vulnerable to severe mental illnesses are the awareness:

1. that a person is suffering from a mental disorder
2. of the effects of medication; and
3. of the social consequences of having a mental disorder.

Treatment

In regard to psychiatric patients, empirical studies verify that, for individuals with severe mental illnesses, lack of awareness of illness is significantly associated with both medication non-compliance and re-hospitalization.

15 percent of individuals with severe mental illnesses who refuse to take medication voluntarily under any circumstances may require some form of coercion to remain compliant because of anosognosia.

One study of voluntary and involuntary inpatients confirmed that committed patients require coercive treatment because they fail to recognize their need for care. Predictably, the patients committed to the hospital had significantly lower measures of insight than the voluntary patients.

Anosognosia is also intimately related to other cognitive dysfunctions that may impair the capacity to continuously participate in treatment. Other research has suggested that attitudes toward treatment can improve after involuntary treatment and that previously committed patients tend to later seek voluntarily treatment.

Neurology

Anosognosia is relatively common following brain injury [ie: 20–30% in the case of hemiplegia / hemiparesis after stroke], but can appear to occur in conjunction with virtually any neurological impairment. However, it is not related to global mental confusion, cognitive flexibility, or other major intellectual disturbance.

Anosognosia can be selective in that an affected person with multiple impairments may only seem unaware of one handicap, while appearing to be fully aware of any others. Those diagnosed with dementia of the Alzheimer's type often display this lack of awareness and insist that "There is nothing wrong with me!".

The condition does not seem to be directly related to sensory loss and is thought to be caused by damage to higher level neurocognitive processes which are involved in integrating sensory information with processes which support spatial or bodily representations [including the somatosensory system].

Anosognosia is thought to be related to unilateral neglect, a condition often found after damage to the non-dominant (usually the right) hemisphere of the cerebral cortex in which sufferers seem unable to attend to, or sometimes comprehend, anything on a certain side of their body (usually the left).