Learn More
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.(More)
CONTEXT Obsessive-compulsive disorder (OCD) is clinically heterogeneous, but it is unclear whether this phenotypic heterogeneity reflects distinct, or partially distinct, etiologic mechanisms. OBJECTIVE To clarify the structure of the genetic and environmental risk factors for the major symptom dimensions of OCD. DESIGN Self-report questionnaires and(More)
BACKGROUND It is not unusual for researchers to make apparently minor modifications to existing instruments without checking if this alters psychometric properties. METHOD Equivalent items on child mental health from two different versions of the Rutter parent questionnaire were compared: items from the standard version and from a modified version. The(More)
A reluctance to discard items, leading to severely cluttered living spaces, is the landmark feature of hoarding disorder (HD). Many, but not all, individuals with HD also excessively acquire, buy or even steal items that they do not need and for which no space is available. In DSM-5, "excessive acquisition" can be coded as a specifier of HD. Despite their(More)
In this genetic study of atypical gender role development, parents of 5,799 twin pairs, ages 3 and 4, rated their twin children's masculinity and femininity. Boys were selected as gender atypical if they were highly feminine (top 5%, 10%, or 15%) relative to other boys, and girls were selected if they were highly masculine relative to other girls.(More)
Traumatic life events and early material deprivation have been identified as potential environmental risk factors for the development of pathological hoarding behavior, but the evidence so far is preliminary and confounded by the presence of comorbid obsessive-compulsive disorder (OCD). This study retrospectively examined the occurrence of(More)
The genetic and environmental etiologies of sex-typed behavior were examined during the preschool years in a sample of 3,990 three- to four-year-old twin and non-twin sibling pairs. Results showed moderate genetic and significant shared environmental influence for boys and substantial genetic and moderate shared environmental influence for girls. For both(More)
Harris argues that peer relationships are the chief determinants of personality development. Harris's thesis makes the behavioral genetic investigation of peer groups particularly timely. The present study examined genetic and environmental contribution to self-reported peer-group characteristics in two samples of adolescent siblings: 180 adoptive and(More)
PURPOSE OF REVIEW 1995 saw the publication of a major review of time trends in psychosocial disorders of youth across the second half of the twentieth century. It found evidence for substantial increases in rates of youth crime, alcohol and drug use, depression and suicide in most industrialized countries in the decades following the Second World War,(More)
Body dysmorphic disorder (BDD) is thought to be etiologically related to obsessive-compulsive disorder (OCD) but the available evidence is incomplete. The current study examined the genetic and environmental sources of covariance between body dysmorphic and obsessive-compulsive symptoms in a community sample of adult twins. A total of 2,148 female twins(More)