Borderline personality disorder and the assessment of witness competence

In Germany there has been a significant increase in the demand of experts' opinions about witnesses with borderline personality disorder, usually putting in doubt their general ability to be a valuable witness. This article aims to explicate and differentiate the basic constructs of statement psychology: witness competence as opposed to the credibility or reliability of a particular statement. Witness competence is defined as a conglomerate of various basic abilities necessary to be able to serve as a witness (and thus as evidence) in court. It will be argued that none of these basic competences are usually impaired in persons with a borderline personality disorder, unless there is evidence for a psychotic episode or severe dissociation.