Huntington's disease (HD) is an inherited neurodegenerative disease that affects nerve cells in the brain leading to mental decline and behavioral symptoms.

Visible signs and symptoms usually appear on people in their 30s or 40s. Sometimes the onset of the disease begins early in life, even before the 20s. In this case the condition is called juvenile Huntington's disease.

Depression is the most common psychiatric disorder associated with Huntington's disease

There is a rating scale used to measure the progress of the disease. This rating system is based on motor, behavioral, cognitive, and functional assessments.

Diagnosis can be confirmed with:

- Physical examination and family history.

- Psychological examination.

- Genetic test, which can confirm the diagnosis in patients without family history of the disease.

CT, MRI or PET scans can help to determine the degree of cerebral atrophy that can be usually seen in the advanced stages of the disease.