Borderline Personality Disorder Study
Study Code:PD
Sample:Twins aged at least 18 years old, 699 subjects
Start Date:Jul.2003
Contact:Anjali Henders
More Info:QIMR only

Specific aims

Aim 1:
To initiate a twin study of the genetics of Borderline Personality Disorder, as well as of the personality dimensions that underlie the symptoms of this disorder.

Aim 2:
To provide data regarding the prevalence of features of BPD in a community sample.

Aim 3:
To conduct genetic analyses of the features of BPD as assessed by the Personality Assessment Inventory-Borderline features (PAI-BOR) scale.10

Aim 4:
To conduct multivariate genetic analyses to determine the extent to which the NEO-PIR2 assesses the same dimensions of genetic variation as do the PAI-BOR items.

The sample consists of approximately 7,000 Australian twin pairs from a birth cohort of 1972 - 1985 (ages 18-31 at the time of the proposed study) obtained through the Australian Twin Registry. All twins will be approached and invited to complete an online questionnaire (45-60 minutes) which contains the following sections: the Personality Assessment Inventory-Borderline Features (PAI-BOR) Scale; revised NEO-Personality Inventory (NEO-PI-R); personal and family details (demographic information); suicide and self-harm; tobacco, alcohol and cannabis use; and general health. The SIDP-IV will be administered as a telephone interview to a sub-sample of 300 respondents - 100 who scored >60 (raw score) on the PAI-BOR (extreme borderline features group; 2 SDs above the community mean); 100 participants who scored between 38-59 (elevated borderline features group; 1 SD above the community mean); and 100 participants who scored less than 38 (low borderline features group).

Research outcome
The completion of this study will move the field forward for several reasons. First, a better estimate of the distribution of BPD features in the community will be obtained. Second, we will be able to estimate the degree of genetic and environmental influence on the manifestation of BPD features, as well as the degree to which borderline features and personality traits have common genetic influences. Finally, completion of this study will set the stage for important future studies: (1) we will seek NIH funding to fully assess all twins in this cohort using Axis I and Axis II structured interviews; and (2) our ascertained sample (along with the similarly ascertained Dutch sample; see Trull & Boomsma application) will provide a large enough sample to conduct linkage and association studies of BPD. Further, the Dutch sample will be used as a replication sample, giving us more confidence in the results obtained.