Huntington's Disease (HD) is a progressive neurological disorder whose cardinal features are involuntary movements and cognitive decline. Severe emotional and/ or psychiatric disturbances are common features of the mental deterioration. When the emotional disturbance precedes the development of the movement disorder, HD is often misdiagnosed as a psychiatric condition. The present case study taken from the University of Texas Neuropathology Museum illustrates these issues. The patient was diagnosed and treated for depression for over a decade before the behavioral and neurological deterioration progressed to the point that an HD diagnosis could be made. Only with the detection of a positive family history and the onset of the hallmark choreiform movements was the final diagnosis of HD made. The patient's behavioral features are presented and current pathological and neuropsychological findings in HD are reviewed and discussed.