Prevalence and heritability of compulsive hoarding: a twin study.
OBJECTIVE
Compulsive hoarding is a serious health problem for the sufferers, their families, and the community at large. It appears to be highly prevalent and to run in families. However, this familiality could be due to genetic or environmental factors. This study examined the prevalence and heritability of compulsive hoarding in a large sample of twins.


METHODS
A total of 5,022 twins completed a validated measure of compulsive hoarding. The prevalence of severe hoarding was determined using empirically derived cutoffs. Genetic and environmental influences on compulsive hoarding were estimated using liability threshold models, and maximum-likelihood univariate model-fitting analyses were employed to decompose the variance in the liability to compulsive hoarding into additive genetic and shared and nonshared environmental factors (female twins only; N=4,355).


RESULTS
A total of 2.3% of twins met criteria for caseness, with significantly higher rates observed for male (4.1%) than for female (2.1%) twins. Model-fitting analyses in female twins showed that genetic factors accounted for approximately 50% of the variance in compulsive hoarding, with nonshared environmental factors and measurement error accounting for the other half.


CONCLUSIONS
Compulsive hoarding is highly prevalent and heritable, at least in women, with nonshared environmental factors also likely to play an important role.
Iervolino
Alessandra C
AC
Department of Psychology, King's College London, Institute of Psychiatry, London SE5 8AF, UK.
Perroud
Nader
N
Fullana
Miguel Angel
MA
Guipponi
Michel
M
Cherkas
Lynn
L
Collier
David A
DA
Mataix-Cols
David
D
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003192:Compulsive Behavior / Q000453:epidemiology* / Q000235:genetics*; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics*; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics