Cognitive and Psychiatric Abnormalities

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Cognitive and Psychiatric Abnormalities
Huntington's Disease: Bridging Clinical and Basic Neurobiology
Matthew O. Hebb, Ph.D (0T2)

Click here to read the full report [1999] which also addresses Motor Abnormalities, Relationship Between HD Pathology and Symptomatology, Molecular Biology of HD, and Hypothesized Role of Huntingtin

Cognitive and Psychiatric Abnormalities
Cognitive and psychiatric abnormalities are common among HD patients. Symptoms include dementia, depression, paranoia, schizophrenia and personality disorders. There also tends to be a high rate of suicide or attempted suicide in this population.The diversity and apparently non-specific mental problems that may arise facilitate misdiagnosis of early stage HD, prior to the onset of motor abnormalities.

Although several reports indicate that psychiatric symptoms occur prior to the onset of chorea or other motor abnormalities, there have also been reports of their occurrence after the onset of motor symptoms.

The personality changes that occur in HD may be subtle in regards to linking them to neurological disease and may consist of increased degrees of antisocial (psychopathic) behavior, irritability, or aggression.

Therefore, the diversity of psychiatric problems produced by HD can make it difficult to assess whether the mental symptoms began after the onset of motor difficulties or if they were present initially but went undetected.

A connection between HD and schizophrenia has been hypothesized for many years. Indeed, several reports have described the misdiagnosis of schizophrenia in patients that were later found to have HD.

Three studies using standardized criteria for diagnosing schizophrenia reported the co-occurrence of HD and schizophrenia in 3/88 (3%),1 9/86 (10%)14 and 8/64 (12%)15 patients.

The etiology of schizophrenia in HD patients remains unclear. There are conflicting opinions as to whether this condition is a direct result of the HD gene mutation or if patients with HD simply have an increased susceptibility to mental disorders.