Multivariate modelling and the Defence Mechanism Test: a comparative study of defensive structures in borderline,...

The study aims at discerning discriminating patterns in the perceptual responses according to the projective percept-genetic method Defence Mechanism Test (DMT) among 45 subjects with the diagnoses borderline personality disorder (BPD), other personality disorders (OPD), schizophrenic disorder (SD) and a non-patient group. The overall results show that, by means of partial least squares (PLS) discriminant analysis of 130 DMT variables, it is possible to separate these groups. Patients with a BPD or a SD diagnosis and the non-patient group are clearly separated, whereas the OPD group shows a less homogeneous pattern. The findings support both the validity of the DMT as a method to measure personality features and the psychodynamic validity of BPD. The most characteristic properties of the BPD group are responses of emotional expressions, especially introaggression and frequent distortions of the stimulus picture. Regarding the SD/OPD group, a pattern of high threshold values for perception emerges as a discriminating feature as well as different variants of introjection. The non-patients are characterized by very few DMT distortions and consequently show a good reality orientation. The conclusion is that the DMT and the PLS discriminant analysis are powerful methods in the assessment of personality pathology.