DAPP-BQ. The Dimensional Assessment of Personality Pathology-Basic Questionnaire (Livesley & Jackson, 2002, 2009; Livesley et al., 1989; Livesley, Jackson, & Schroeder, 1992) is a 290-item; self-report questionnaire with the items rated on a 5-point scale ranging from 1 (Very unlike me) to 5 (Very like me).
The short form of DAPP-BQ (Dutch language version), called DAPP-SF, was derived by van Kampen et al.
Structural Equation Modeling (SEM) has been used to assess each DAPP-BQ scale.
The means, standard deviations, kurtosis, skewness and alphas for the 18 DAPP-BQ (3) scales including the 290, 136 and 90-items forms are shown in Table 1.
DAPP-BQ and DAPP-SF mean differences between studies
Maximum likelihood confirmatory factor analyses were conducted over the variance-covariance matrices of each DAPP-BQ single scales in the three versions of the test for both random groups (1 and 2).
Table 2 compares the goodness-of-fit indices for each DAPP-BQ factors for the full 290-item, 136-item and 90-item forms.
This strategy was performed separately for both groups of participants (1 and 2), and for all participants; b) we intended to obtain a satisfactory fit on SEM adjustment values (TLI > .90 and RMSEA < .05) for each DAPP-BQ scale in both separate groups (calibration and validation), and simultaneously for the whole sample.
Table 3 shows the factorial structure of the separate scales of the DAPP-BQ, DAPP-SF, and DAPP-90, leaving out of consideration the three Self-Harm scales that were found to have very large kurtosis and skewness values.
In this study we tested that the DAPP-BQ dimensions were higher in patients with psychosis than in siblings of this type of patients, as we expected.
SSLS, however, had a more adaptive personality, reflected by their low scores on DAPP-BQ. This profile, that distances them from patients, and from SSHS, could be a protective factor to them for psychosis.
In this study we found that a DAPP-BQ pathological personality profile characterized by high scores on the dimensions of affective lability, anxiousness, submissiveness, social avoidance, identity problems, oppositionality, narcissism, and restricted expression, can distinguish between siblings who had more schizotypal features and those who had less.