Both a strong tendency to criticize others and delusional hostility may be
present long before the classic and defining symptoms of Huntington's disease
appear, a new study has found.
The study was headed by Evangelos Vassos, M.D., and conducted while he was
a research fellow at the University of Athens in Greece. He is currently an
honorary research associate at the Institute of Psychiatry in London. Results
are in press with Biological Psychiatry.
Sixty-four subjects with a first-degree relative with Huntington's disease
participated in the study. They were on average in their early 30s and thus 16
years younger than the usual age of onset for Huntington's. All knew that they
had a 50 percent chance of carrying the mutated gene that causes the disease
and thus getting the disease themselves.
The subjects were evaluated for psychiatric symptoms using the Structured
Clinical Interview for DSM-IV (SCID), Mini Mental State Examination,
Symptom Checklist 90, Snaith Irritability Scale, Hostility and Direction of
Hostility Questionnaire, and Maudsley Obsessive Compulsive Inventory. At this
point, neither the subjects nor Vassos, who evaluated them, knew who had the
gene and who did not.
After that evaluation the subjects were genotyped. Twenty-nine were found
to carry the Huntington's gene, while 35 did not. Vassos and his coworkers
then assessed whether there were any psychiatric differences between those
with the mutated gene and those without it.
The groups were comparable on cognitive state and general functioning.
However, extroverted hostility was more often present in subjects who carried
the gene, and the difference was highly statistically significant. The
researchers then looked to see whether there was any significant link between
having the Huntington's gene and having any of the three subtypes of
extroverted hostility—criticism of others, delusional hostility (for
example, "I believe I am being plotted against"), or acting out.
They found a link for criticism of others and delusional hostility, but not
for acting out. No link appeared between the presence of extroverted hostility
in subjects and their expected time of disease onset.
These results indicate "that gene carriers have higher levels of
extroverted hostility than noncarriers," Vassos and his colleagues said
in their report. "In line with this is the finding that extroverted
hostility is not affected by the proximity to the age of onset of
Huntington's, which suggests that gene carriers have a stable pattern of
increased hostility starting apparently long before the onset of the
disease... [and that this increased extroverted hostility] is not just
reactive to the manifestation of the disease."
In short, they concluded, extroverted hostility is an early marker for
Commenting on the implications of his findings in an interview with
Psychiatric News, Vassos pointed out that there is no cure for
Huntington's disease and no treatment preventing the development of the
disorder or specific treatment for the hostility found in subjects at genetic
risk. However, various drugs, particularly antipsychotics, have been used to
treat abnormal movements, and antidepressants and mood stabilizers have been
used to treat affective and behavioral problems related to the disease.
Vassos added that educating patients and their families about the
possibility of some symptoms of hostility being explained by the mutated gene
might reduce patients' guilt and unnecessary animosity within families.
Finally, these findings might help during counseling or psychotherapy with
individuals at risk of developing Huntington's.
"Overall, this study gives some insight that although Huntington's
disease has traditionally been considered a neurological disease, there is
scope for collaboration with psychiatry," Vassos told Psychiatric
News. "Clinical neurologists need to be aware of psychiatric
manifestations of the disease—studies have indicated that emotional
disturbances in Huntington's are often overlooked—and clinical
psychiatrists need to acquire training in treating neuropsychiatric
The study received no outside funding.
An abstract of "Higher Levels of Extroverted Hostility
Detected in Gene Carriers at Risk for Huntington's Disease" is posted at<www.journals.elsevierhealth.com/periodicals/bps/article/PIIS0006322306015836/abstract>.▪