Sampling Methods in Personality Pathology Research: Some Data and Recommendations

The field of personality disorder research has grown since the publication of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, in 1980; with a notable evolution in the way that personality disorders are defined and operationalized. In evaluating this research, it is necessary to consider the range of sampling practices used. The goal of this study was to describe current sampling methods in personality disorder research and provide recommendations to guide sample design in future personality disorder research. To do this, we coded sampling practices described in recent empirical articles published in four journals that showcase research on personality disorders. We summarized aspects of sampling design including the combination of study question and sample characteristics (e.g., sample size, sample source, and use of screening), study design, and demographic representation of samples. Findings reveal a need for studies to better consider whether their samples are fit for purpose and to make explicit their target population and sampling frame, as well as the specific procedures (i.e., recruitment) used to carry out sampling. We also discuss issues that arise when attempting to capture low-base rate pathology, which is often associated with high comorbidity. We emphasize a process-oriented approach to developing a sampling strategy for personality disorders research.